Okay,,, just a real, real quick update... I mean it is Friday after all and I have a b-ball game tomorrow morning - well my son does but I'm the assistant coach.
Just had a chance to look at the 00z runs of the NAM / GFS... One might say that the storm is trending southeast if you compared the last 2 NAM runs but I think this solution is out to lunch as far as the track is concerned... I don't think the NAM has a handle simply because remember the NAM is a mesoscale model and the jet energy that eventually develops into this storm is still outside of the NAM's grid. The GFS is a spectral model and is probably going to be a little closer to the actual track. I really don't like to pin down a storm track based on GFS model data if the storm is still beyond 84 hours, but I do watch the "trending" of the track very closely. And the trend is farther north and west. Bottom line the previous blog (Friday midday update) detailed discussion still looks to be dead on!
No doubt, I'll keep you updated as needed on this blog and Bob Symon and Kim Stevens will have the latest, most accurate advanced warning forecast for you all weekend on NewsChannel 32.
If you have a few seconds, drop me a line with your thoughts. Have a great weekend and enjoy the weather
Later:
Jay
Friday, February 29, 2008
Friday Midday Update
That was an interesting 6 hour period... At around 2am last night it was a r-/s- mix. This morning at 8am, I looked out my window and saw 2 CGs and had about 20 seconds of marble sized hail !!. That's some serious changes in our atmosphere. Actually strong WAA responsible for the above mentioned events.
Clipper system slides to our northeast today. Trailing cold front expected to slip through here this evening. But by far, the coldest air with this system will bypass our region to the northeast.
The weekend looks pretty good. Nice way to welcome in the new month ! Surface high pressure and upper level ridging will control our weather pattern for the weekend.
Sfc high on top of us tomorrow ensuring lots of sunshine with just a few mid/high clouds expected later in the day and evening.
Clipper system slides to our northeast today. Trailing cold front expected to slip through here this evening. But by far, the coldest air with this system will bypass our region to the northeast.
The weekend looks pretty good. Nice way to welcome in the new month ! Surface high pressure and upper level ridging will control our weather pattern for the weekend.
Sfc high on top of us tomorrow ensuring lots of sunshine with just a few mid/high clouds expected later in the day and evening.
Sfc high shifts east Saturday night allowing for a massive WAA pattern to set up over the Ohio Valley. On Sunday, breezy south winds will warm our temps easily into the upper 50s / low 60s.
I do think we will see an increase in cloud cover as H9 & H85 moisture values progged to jump to 90% or better by midday (BKN stratoCu deck likely Sunday afternoon)
I do think we will see an increase in cloud cover as H9 & H85 moisture values progged to jump to 90% or better by midday (BKN stratoCu deck likely Sunday afternoon)
Alright, that's leads me to early next week. A frontal boundary will slowly approach from the west. The front is progged to slip through here (slowly) Monday afternoon. Shower chances will increase at this time as most if not all the rain is expected to be post frontal.
Front will stall very close to us (likely just east) as upper flow backs in response to strong H5 short developing in the southern stream. This shortwave will make for a very wet Monday night and Tuesday across the region - as a matter of fact we could be looking at flooding issues with this thing.
Sfc low pressure will develop on the boundary over the lower MS valley and rapidly deepen as it works northeast towards the Ohio Valley.
Massive overrunning / WAA will develop with rain and thunderstorm activity exploding over the region Monday night into Tuesday - Looks to me that the greatest potential for SVR will be to our south, but no doubt elevated type storms are likely close to us (i.e. hail producers ??)
System expected to bomb out over us. Exact track is still of course up in the air but will become more clear by Saturday afternoon. At this time, sfc system looks to track just southeast of our region with the upper system pretty much right over us.
This track would mean a mainly rain event for the local area. Yes, still a chance for snow on the backside, but it would be quite light if this track pans out. The big snow would take place off to our west and northwest. Those same areas that have gotten hammered this season so far... look to be in line again - only this one could be the biggest of their season so far with even blizzard conditions a real possibility - man, they have all the luck !! - You can tell I'm a snow lover.
We'll certainly keep you posted, in the meantime, have a wonderful weekend and enjoy the warm up !!
Later
Jay
Later
Jay
Thursday, February 28, 2008
Wednesday Night Update
Oh, boy here we go ....... the hype is already starting with some folks !! The GFS 6 and 7 day fcst is out and painting a rain to snow scenario - and during the time of snowfall putting down quite a bit in our area... I'm a snow lover too but to go out and say possible amounts for a storm that clearly has not even formed and disappears on one run only to reappear on the next ....!!!!
I mean c'mon, that's just hype (certainly not meteorology) but just hype!!.
So let's talk real weather for a second...
First of all, a clipper type system will be tracking southeast across the Great Lakes region Thursday night through Friday. Strong WAA will set up across the Ohio Valley starting tomorrow into tomorrow night. After some sunshine Thursday morning, mid and high level moisture will rapidly begin increasing over the area. Clouds will continue to thicken Thursday night. As the ceilings lower, some patchy light precipitaion will be possible after midnight. If the precip begins early enough, there may be some wet snow at the onset before it quickly goes over to all rain late Thursday night into Friday - especially north and northeast of Louisville.
A vort lobe will sweep the Ohio Valley on Friday with a decent area of showers ahead of it. During the afternoon, rapid drying at H7 and above will bring a quick end to the rain.
I mean c'mon, that's just hype (certainly not meteorology) but just hype!!.
So let's talk real weather for a second...
First of all, a clipper type system will be tracking southeast across the Great Lakes region Thursday night through Friday. Strong WAA will set up across the Ohio Valley starting tomorrow into tomorrow night. After some sunshine Thursday morning, mid and high level moisture will rapidly begin increasing over the area. Clouds will continue to thicken Thursday night. As the ceilings lower, some patchy light precipitaion will be possible after midnight. If the precip begins early enough, there may be some wet snow at the onset before it quickly goes over to all rain late Thursday night into Friday - especially north and northeast of Louisville.
A vort lobe will sweep the Ohio Valley on Friday with a decent area of showers ahead of it. During the afternoon, rapid drying at H7 and above will bring a quick end to the rain.
The system clears the Ohio Valley just in time to be us a nice first weekend of March. Cool for Saturday but massive WAA Saturday night will bring a nice warm up for Sunday.
Alright, this brings me to the system for next week. First of all, those folks that are talking massive snow for Louisville next week are looking at the GFS only - NOT smart. The GFS has been all over the place with next week's potential system - and I mean all over !! At this time the only thing the GFS is good for is saying that a storm system is possible early next week - and that's IT.
Okay so what about the other MRF models. The Euro, Canadian, UKMET, Nogaps, all suggest substantial energy in both streams. Kind of looks like the northern stream energy will shove a frontal boundary through the region during the Monday time frame with good chances for rain. This frontal boundary will slow sigificantly as the upper flow begins backing in response to the southern energy working east through Texas. Cyclogenisis should occur on the boundary over the lower Mississippi valley and then the low working northeast towards us. At this time most of the models track the upper energy and surface low to out southeast. Yes, that is typically a good track for snow here but there are a couple of things bothering me with this track. 1) Persistance....every storm coming from the southwest this year has either gone right over us or just north. That's why there's been record snow in the upper midwest this season - I wouldn't be a bit surprised to see this thing trending north as we get closer to the actual event. 2) Lack of cold air....??? Notice that this southern system is pretty far south of the polar stream. Many of the MRF models have the polar stream running well north across Canada. That ain't good if you want a good, deep cold air source for a great big winter storm - (I would like to see the polar stream diving into the eastern Lakes / Eastern Ohio valley for substantial cold air) So.... this storm is going to almost have to generate its own cold air. And yes, big upper-level storms can do this - but typically the snow area with systems like this are relatively small in size (with regards to typical synoptic scale snowstorms) and found very close to the H5 circulation (i.e. under the low).
So is there a chance for some snow with this system - sure there is, how much ?? and will it be a massive amount ???? no idea because it is way too early to even suggest it and is, well... frankly, just plain irresponsible.
We'll watch it close and keep you updated - without the hype.
Have a great thursday
Jay
Okay so what about the other MRF models. The Euro, Canadian, UKMET, Nogaps, all suggest substantial energy in both streams. Kind of looks like the northern stream energy will shove a frontal boundary through the region during the Monday time frame with good chances for rain. This frontal boundary will slow sigificantly as the upper flow begins backing in response to the southern energy working east through Texas. Cyclogenisis should occur on the boundary over the lower Mississippi valley and then the low working northeast towards us. At this time most of the models track the upper energy and surface low to out southeast. Yes, that is typically a good track for snow here but there are a couple of things bothering me with this track. 1) Persistance....every storm coming from the southwest this year has either gone right over us or just north. That's why there's been record snow in the upper midwest this season - I wouldn't be a bit surprised to see this thing trending north as we get closer to the actual event. 2) Lack of cold air....??? Notice that this southern system is pretty far south of the polar stream. Many of the MRF models have the polar stream running well north across Canada. That ain't good if you want a good, deep cold air source for a great big winter storm - (I would like to see the polar stream diving into the eastern Lakes / Eastern Ohio valley for substantial cold air) So.... this storm is going to almost have to generate its own cold air. And yes, big upper-level storms can do this - but typically the snow area with systems like this are relatively small in size (with regards to typical synoptic scale snowstorms) and found very close to the H5 circulation (i.e. under the low).
So is there a chance for some snow with this system - sure there is, how much ?? and will it be a massive amount ???? no idea because it is way too early to even suggest it and is, well... frankly, just plain irresponsible.
We'll watch it close and keep you updated - without the hype.
Have a great thursday
Jay
Wednesday, February 27, 2008
Tuesday Night Update
Talk about a wintry night across the region !! Most snowfall amounts have been an inch or less although I did get a report of an inch and a half from my good friend and weather intern Jared in Henryville, IN - thanks man !
Broad northwest flow to continue over the region the next day or so... H85 and H9 temperatures progged to be quite cold for this time of year. Mixing H85 #'s for Wednesday gives you temps ranging from 27 to 29 around the area--- ouch !! That's cold stuff for late February !
Latest (00z) NAM also keeps H85 layer 90% or better for much of the day.
Think we'll hold on to mostly cloudy skies with a few flurries as temps in the cloud layer will be plenty cold for ice crystals.
New gridded data (00z NAM) suggesting that low clouds should eventually break up Wednesday night. Could it be ????????? some sunshine for Thursday???? maybe a little in the morning but mid/high level moisture (warm advection) progged to rapidly increase from the northwest by Thursday afternoon. So our sunshine propects for Thursday may be quite limited.
Anyway, these mid/high clouds will be increasing ahead of our next weather-maker. A rather energetic H5 short will be slipping southeast across the Great Lakes region on Friday along with its surface features. Showers will become likely on Friday - but I don't think they will be all that heavy. Earlier runs of the GFS were really blowing up some decent QPF (rain) for the region. But given how far north the best dynamics are, WAA zone/convergence zones, Gulf NOT open for business - this QPF looks really overdone. But still a few showers likely as system passes to our north and northeast.
This system should clear the region just in time for the first weekend of March. At this time, it looks like a nice weekend is on the way. New 00z H85 temps are suggesting that highs on Saturday could be well into the 50s and highs on Sunday closing in on the 60s (although with a progged 50 kt LLJ over the region Sunday afternoon - it looks to be quite gusty).
have a great Wednesday all,
Later:
jay
Broad northwest flow to continue over the region the next day or so... H85 and H9 temperatures progged to be quite cold for this time of year. Mixing H85 #'s for Wednesday gives you temps ranging from 27 to 29 around the area--- ouch !! That's cold stuff for late February !
Latest (00z) NAM also keeps H85 layer 90% or better for much of the day.
Think we'll hold on to mostly cloudy skies with a few flurries as temps in the cloud layer will be plenty cold for ice crystals.
New gridded data (00z NAM) suggesting that low clouds should eventually break up Wednesday night. Could it be ????????? some sunshine for Thursday???? maybe a little in the morning but mid/high level moisture (warm advection) progged to rapidly increase from the northwest by Thursday afternoon. So our sunshine propects for Thursday may be quite limited.
Anyway, these mid/high clouds will be increasing ahead of our next weather-maker. A rather energetic H5 short will be slipping southeast across the Great Lakes region on Friday along with its surface features. Showers will become likely on Friday - but I don't think they will be all that heavy. Earlier runs of the GFS were really blowing up some decent QPF (rain) for the region. But given how far north the best dynamics are, WAA zone/convergence zones, Gulf NOT open for business - this QPF looks really overdone. But still a few showers likely as system passes to our north and northeast.
This system should clear the region just in time for the first weekend of March. At this time, it looks like a nice weekend is on the way. New 00z H85 temps are suggesting that highs on Saturday could be well into the 50s and highs on Sunday closing in on the 60s (although with a progged 50 kt LLJ over the region Sunday afternoon - it looks to be quite gusty).
have a great Wednesday all,
Later:
jay
Tuesday, February 26, 2008
Monday late night update
Just talked to my brother on the southwest side of Chicago..... Silver-dollar sized flakes and snowing at the rate of 1 to 2 inches / hr !!! He says it's so bright out it looks like the middle of the day.
That's gotta be one of my favorite things that happens when you get a big snowstorm at night - how bright it is in the middle of the night !!
Well, we are on the warm air side of the storm.... bottom line, another storm taking just about the same track they all have so far this winter season - right up through the lower Ohio Valley into the Northeast... That's why the Great Lakes have gotten absolutely hammered with snowfall so far this year.
Sfc low pressure will continue to track through the area overnight. Occasional showers will also continue but gradually diminish to some spotty drizzle by morning Tuesday.
No problems on the roadways overnight through much of tomorrow as temperatures will stay above the 32 degree mark. Strong CAA will take hold during the day into Tuesday night. H85 temps progged to drop from -14 to -17C and saturated as well Tuesday night into Wednesday. In addition, a strong secondary vort max will be tracking southeast on the backside of the upper trough that will be located over the region. As this energy shifts through the region, some of the remaining moisture over the area will get squeezed out in the form of light snow and flurries. May see flurries and patchy light snow as early as Tuesday afternoon, but it should not accumulate that much with sfc temps above 32 degrees. Our LIGHT accumulations will come Tuesday night as temperatures drop below freezing.
Certainly not a lot of snowfall is expected but a light coating is likely in many areas -generally a dusting to around an inch across just about all of the region Tuesday night into Wednesday morning.
Cold temperatures will blow into the region on gusty northwest winds. Temps easily dropping into the lower 20s Tuesday night coupled with the light snow showers and flurries could make for some icy spots overnight Tuesday and Wednesday morning.
Temperatures will slowly recover to the mid/upper 20s on Wednesday, but that should be about it.
Stay warm and have a great Tuesday
Later:
Jay
That's gotta be one of my favorite things that happens when you get a big snowstorm at night - how bright it is in the middle of the night !!
Well, we are on the warm air side of the storm.... bottom line, another storm taking just about the same track they all have so far this winter season - right up through the lower Ohio Valley into the Northeast... That's why the Great Lakes have gotten absolutely hammered with snowfall so far this year.
Sfc low pressure will continue to track through the area overnight. Occasional showers will also continue but gradually diminish to some spotty drizzle by morning Tuesday.
No problems on the roadways overnight through much of tomorrow as temperatures will stay above the 32 degree mark. Strong CAA will take hold during the day into Tuesday night. H85 temps progged to drop from -14 to -17C and saturated as well Tuesday night into Wednesday. In addition, a strong secondary vort max will be tracking southeast on the backside of the upper trough that will be located over the region. As this energy shifts through the region, some of the remaining moisture over the area will get squeezed out in the form of light snow and flurries. May see flurries and patchy light snow as early as Tuesday afternoon, but it should not accumulate that much with sfc temps above 32 degrees. Our LIGHT accumulations will come Tuesday night as temperatures drop below freezing.
Certainly not a lot of snowfall is expected but a light coating is likely in many areas -generally a dusting to around an inch across just about all of the region Tuesday night into Wednesday morning.
Cold temperatures will blow into the region on gusty northwest winds. Temps easily dropping into the lower 20s Tuesday night coupled with the light snow showers and flurries could make for some icy spots overnight Tuesday and Wednesday morning.
Temperatures will slowly recover to the mid/upper 20s on Wednesday, but that should be about it.
Stay warm and have a great Tuesday
Later:
Jay
Monday, February 25, 2008
Monday morning update
Another decent storm system for the Ohio Valley. Energy from this system continues to be further and further south as easc model run has been coming out since late last week. Latest 12Z runs now have the lead H5 short/vort max passing virtually on top of us tomorrow morning !!
This , of course, also means that the sfc low with this system is passing much farther south and also pretty much right over our area late tonight / tomorrow morning.
This , of course, also means that the sfc low with this system is passing much farther south and also pretty much right over our area late tonight / tomorrow morning.
Models also suggest a good slug of moisture in here tonight/tomorrow. As sfc low/triple point pass through the region, there could be a narrow ribbon of weak instability passing through...check out the MLCAPE from last night's 00Z GFS.
This weak instability combined with good dynamic forcing means a good round of showers with even some thunder embedded within.
System shifts northeast tomorrow morning. Strong CAA throughout day sends temperatures below critical by late morning as a changeover to snow takes place. This is where things get a little interesting and some model divergence takes place. NAM still has a big area of 90% + wrap around moisture shifting through the region along with decent lift. This deep moisture extends all the way down to the TN/MS-AL line !! This wrap-around moisture looks overdone/too far south considering the wave/H5 energy is 1) not closed off, 2) accelerating towards a confluent flow, 3) moving northeast. In this pattern, the wrap around / def zone is north / northwest of the H5 vort and should be shifting NE with the vort - NOT expanding and moving due east / moving southeast as the NAM has it. GFS 12Z model data looks better with it's placement / moisture pattern during the day Tuesday.
Having said all this... sensible weather-wise, rain changes to snow tomorrow with periods of light snow and flurries tomorrow late/morning into tomorrow night - with even some flurries lingering into Wednesday morning. Accumulations look to be quite light and mainly on grassy areas during the day Tuesday. Up to an inch or two possible in the far northern counties of the viewing area with amounts diminishing as you shift south towards the Ohio river into Kentucky.
Real cold air should arrive tomorrow night as 2nd H5 shortwave shifts south through the mean trough over the region. H85 temps drop from -15 to -18C behind this secondary wave. In addition, NAM still showing levels saturated (i.e. H9 & H85) into Wednesday morning in the good ice crystal (dentrite) layer. Bottomline - a wintry Wednesday expected with flurries, blustery conditions and temps likely holding in the 20s for highs !! Ouch.
Another Update tonight gang..
Have a great Day
Later:
Jay
Sunday, February 24, 2008
Sunday morning quick update
As I discussed in the previous post, fast moving H5 short cruising through the region today. Def zone / comma head on northern side of this vort is producing a band of light snow. Light snow will continue for several hours for the northern half of the viewing area.. 12z NAM spitting out .1 to .15" in this band and it should be mainly snow. Locations under this band (including Louisville) should see 1/2" to an inch of snow on grassy areas. Sfc temps pretty much above freezing so roadways will be just wet.
See previous discussion for Monday and Tuesday's weather expectations.
have a good Sunday
Later:
Jay
See previous discussion for Monday and Tuesday's weather expectations.
have a good Sunday
Later:
Jay
Saturday, February 23, 2008
Saturday late day update...
I realize as of Saturday early evening, no forecasts in the area are mentioning any precip for us on Sunday but....
certainly looks like a mix of light snow and light rain on the way as a fast moving H5 short slides east across the lower Ohio and Tennessee valleys. Does not look to be anything major, but certainly enough for a period of light snow (and some light rain if sfc temps can warm to 37 or better)...
Monday looks to be a decent day... not a lot of sunshine as mid / high clouds rapidly increase ahead of the another system that will impact our region with showers Monday night - but at least temps will moderate. It looks to me that the temperatures will indeed have a tough time reach the 50s though, I look for readings to top out in the 40s. At least it'll warmer than it has been recently. Sfc warm front won't make it to our area during the day on Monday... primarily because the upper system and sfc low(out west) to an extent is still dropping south of east somewhat. When that happens... the thermal patterns tend to become locked down until the upper system bottoms out and starts moving more east/northeast.
System tracks through Monday night with scattered showers.
Tuesday looks to be a transtional day, CAA all day with dropping temperatures but mnot much precip... basically just some drizzle at best.
Tuesday evening, another H5 short will be diving down through the trough. All models have a decent area of moisture translating through the Ohio Valley Tuesday evening (H7 - 90% or better!). Good chunk of atmosphere is saturated and below critical with temperatures is the good ice crystal generation region
Bottomline, should be a batch of light snow and flurries moving through with the second H5 short Tuesday night... Not a big snow certainly, but a few spots could pick up a light coating...
Have a great rest of your weekend and tell me your thoughts if you have a few seconds
later:
Jay
certainly looks like a mix of light snow and light rain on the way as a fast moving H5 short slides east across the lower Ohio and Tennessee valleys. Does not look to be anything major, but certainly enough for a period of light snow (and some light rain if sfc temps can warm to 37 or better)...
Monday looks to be a decent day... not a lot of sunshine as mid / high clouds rapidly increase ahead of the another system that will impact our region with showers Monday night - but at least temps will moderate. It looks to me that the temperatures will indeed have a tough time reach the 50s though, I look for readings to top out in the 40s. At least it'll warmer than it has been recently. Sfc warm front won't make it to our area during the day on Monday... primarily because the upper system and sfc low(out west) to an extent is still dropping south of east somewhat. When that happens... the thermal patterns tend to become locked down until the upper system bottoms out and starts moving more east/northeast.
System tracks through Monday night with scattered showers.
Tuesday looks to be a transtional day, CAA all day with dropping temperatures but mnot much precip... basically just some drizzle at best.
Tuesday evening, another H5 short will be diving down through the trough. All models have a decent area of moisture translating through the Ohio Valley Tuesday evening (H7 - 90% or better!). Good chunk of atmosphere is saturated and below critical with temperatures is the good ice crystal generation region
Bottomline, should be a batch of light snow and flurries moving through with the second H5 short Tuesday night... Not a big snow certainly, but a few spots could pick up a light coating...
Have a great rest of your weekend and tell me your thoughts if you have a few seconds
later:
Jay
Thursday, February 21, 2008
Thursday morning update...
Forecast seems to be on track. Freezing rain and sleet now spreading across the region... with even a snow burst mixed in at the onset. Again, with moderate WAA in place and the moisture overrunning the cold air, this will be mainly an ICE event for the viewing area -
An ICE STORM WARNING has been issued for the area until 9am EST. The Ice storm warning looks dead on but the end time ..?? Looks as if the freezing precip will change to rain in Louisville around midnight (give or take some) and towards daybreak for the far northern areas.
Please use extreme caution when and if traveling today and this evening as untreated roadways will be extremely slick and hazardous...
I'll keeeo you updated
Later:
Jay
An ICE STORM WARNING has been issued for the area until 9am EST. The Ice storm warning looks dead on but the end time ..?? Looks as if the freezing precip will change to rain in Louisville around midnight (give or take some) and towards daybreak for the far northern areas.
Please use extreme caution when and if traveling today and this evening as untreated roadways will be extremely slick and hazardous...
I'll keeeo you updated
Later:
Jay
Wednesday Night Update
Winter weather event still on target for Thursday afternoon and evening....
Arctic high has bulit into the region bringing some very cold air to the Ohio Valley. This Arctic air mass won't last long however, and it will be eroded away from top to bottom across the region.
In other words, a strong H5 short in the southern stream and a potent H5 short in the northern stream will combine to bring a large area of WAA and overrunning cloudiness and precip to the area starting Thursday afternoon and lasting into Friday.
Arctic high has bulit into the region bringing some very cold air to the Ohio Valley. This Arctic air mass won't last long however, and it will be eroded away from top to bottom across the region.
In other words, a strong H5 short in the southern stream and a potent H5 short in the northern stream will combine to bring a large area of WAA and overrunning cloudiness and precip to the area starting Thursday afternoon and lasting into Friday.
Although surface temperatures will be plenty cold and below freezing, I don't think there will be much snow with this event. Moderate WAA will spread warmer air aloft into the Ohio Valley Thursday. At the onset of the precip, there will likely be some sleet and even a few flakes mixed in (better chances for the snow north of Louisville), but as the WAA continues, a rather large region (~920 to 800mb) will be well above critcal by 00Z Friday with that zone increasing to a nearly 200mb thick layer (950 to 750mb) of above critical temps by 03Z Friday!
Bottomline... freezing rain !!! As far as the wintry weather is concerned, freezing rain should be the primary p-type through midnight Thursday night. After midnight, the WAA will win out and warm sfc temps above critical ending the freezing rain in Louisville and then in the far northern areas by daybreak Friday.
Some icing is expected along and north of a E'town to Bardstown line. Ice accumulations will be quite light down near the E'town and Bardstown areas but increase upwards to near a 1/4 inch closer to Louisville and perhaps as much as a 1/2 inch along and north of a Jasper, IN to Madison, IN line. The far southern regions area may have a little sleet or light freezing rain at the onset Thursday afternoon, but temperatures will quickly go above above freezing keeping any icing to a minimum.
Good ole' fashion rainfall is expected everywhere for Friday washing much of the icing away.
Have a great night and Thursday and be careful when traveling.
Later:
Jay
Some icing is expected along and north of a E'town to Bardstown line. Ice accumulations will be quite light down near the E'town and Bardstown areas but increase upwards to near a 1/4 inch closer to Louisville and perhaps as much as a 1/2 inch along and north of a Jasper, IN to Madison, IN line. The far southern regions area may have a little sleet or light freezing rain at the onset Thursday afternoon, but temperatures will quickly go above above freezing keeping any icing to a minimum.
Good ole' fashion rainfall is expected everywhere for Friday washing much of the icing away.
Have a great night and Thursday and be careful when traveling.
Later:
Jay
Wednesday, February 20, 2008
Tuesday Night Update
Well, the first fast-moving system is sliding through the region tonight / early tomorrow.
Patchy light snow and flurries across about the northeast half of the viewing area... Certainly not a big storm but decent WAA in the low layers creating decent (short-lived) verticals for a brief period of the light snow and flurries. Did a detailed analysis of the low layers earlier tonight just as the new 00z NAM and RUC came down... Best little snow area seemed to be located along and north of the H95 front / low track. That would place the 1 to 2 inch amounts basically along and north of a Bedford / Mitchell, IN to Madison, IN line. South of that line and closer to Louisville... a dusting to less than 1 inch amounts expected.
Strong CAA behind this little clipper for Wednesday will ensure falling afternoon temps back into the 20s.
Patchy light snow and flurries across about the northeast half of the viewing area... Certainly not a big storm but decent WAA in the low layers creating decent (short-lived) verticals for a brief period of the light snow and flurries. Did a detailed analysis of the low layers earlier tonight just as the new 00z NAM and RUC came down... Best little snow area seemed to be located along and north of the H95 front / low track. That would place the 1 to 2 inch amounts basically along and north of a Bedford / Mitchell, IN to Madison, IN line. South of that line and closer to Louisville... a dusting to less than 1 inch amounts expected.
Strong CAA behind this little clipper for Wednesday will ensure falling afternoon temps back into the 20s.
Upper level convergence across the northern / eastern Ohio Valley Wednesday night should dictate as to where the cold high pressure will build. Low layers of the atmosphere will chill quite nicely in advance of the next southern stream shortwave.
New 00z runs are forecasting light wintry precip to develop here for Thursday afternoon into Thursday night. Right now that looks okay to me.... I don't think it'll be all that heavy. LLJ really not all that strong - generally 30 to 35kts at H85. Looks decent considering the H5 shortwave is still way back in Eastern NM, west TX at 00z Friday. Heck, there's even a shortwave ridge off to our west across the lower Mississippi valley north into Southeast NE. If anything, the LLJ speeds MAY be overdone and the overrunning precip across our area end up being lighter than what the models are suggesting. Even so, the precip that does occur Thursday afternoon and evening will be messy with the low level cold air in place. Looks like a light snow scenario to start then a rather quick transition to a brief period of sleet before we go over to light freezing rain / freezing drizzle. It appears enough low level warming will take place late Thursday night to change the freezing precip to a cold rain.
At this time it does not look like a lot of icing will take place but.... as you know, it doesn't take much to make a mess on the roadways...
let me know your thoughts ....
Take care and have great Tuesday night and Wednesday.
Later:
Jay
let me know your thoughts ....
Take care and have great Tuesday night and Wednesday.
Later:
Jay
Monday, February 18, 2008
Monday late night update...
Looks cold and quiet through Tuesday night... Another Arctic boundary will pass through Wednesday early morning as a clipper type system swings through the Great Lake states and the northern Ohio Valley. The vort max, H85 - H95 lows pass well north of us. Even the sfc low goes north of us... The GFS runs (excluding the new 00z run (haven't seen it yet)) have been spitting out enough QPF here to support some accumulating snow late Tuesday night into Wednesday morning....???? No way !! I don't buy that solution. I see a few flurries with frontal passage but that's about it. With clipper systems, typically most of the snow is north of the sfc low track with any decent accumulating snows along and north of the H925 low track - and that will be occurring well north of our region.
Cold arctic high builds in for Wednesday night and Thursday morning. A shortwave trough will be dropping south through the northern Plains states inthe northern branch. At the same time, a shortwave will be moving through the Texas / southern Plains region in the subtropical jet. As these two features move east, a broad southwesterly WAA flow will set up and point itself towards our area. Bottomline, clouds should rapidly increase later Wednesday night with moisture overruning the cold air in place across the Ohio Valley. East / northeast winds in the boundary layer and thick clouds should ensure that sfc temps stay below freezing throughout the day. An icy mix of sleet and then freezing rain is expected to overspread our area during Thursday afternoon. If the precip starts early enough even some snow will be possible at the onset. It's still a little early to talk about exact precip type, start time, end time, etc... but just know that Thursday (especially afternoon and evening) has the potential to become quite messy with an icy mix across the region.
Enough warming should take place overnight Thursday to change any ice to a cold rain...
We'll keep you posted and I'll have a detailed update with maps/model support tomorrow (Tuesday)
Sorry for the lack of maps tonight but I gotta get home early tonight.
have a great night and stay warm
Later:
Jay
Cold arctic high builds in for Wednesday night and Thursday morning. A shortwave trough will be dropping south through the northern Plains states inthe northern branch. At the same time, a shortwave will be moving through the Texas / southern Plains region in the subtropical jet. As these two features move east, a broad southwesterly WAA flow will set up and point itself towards our area. Bottomline, clouds should rapidly increase later Wednesday night with moisture overruning the cold air in place across the Ohio Valley. East / northeast winds in the boundary layer and thick clouds should ensure that sfc temps stay below freezing throughout the day. An icy mix of sleet and then freezing rain is expected to overspread our area during Thursday afternoon. If the precip starts early enough even some snow will be possible at the onset. It's still a little early to talk about exact precip type, start time, end time, etc... but just know that Thursday (especially afternoon and evening) has the potential to become quite messy with an icy mix across the region.
Enough warming should take place overnight Thursday to change any ice to a cold rain...
We'll keep you posted and I'll have a detailed update with maps/model support tomorrow (Tuesday)
Sorry for the lack of maps tonight but I gotta get home early tonight.
have a great night and stay warm
Later:
Jay
Sunday, February 17, 2008
Sunday Afternoon Update
Hello all... it's windy out there but the near 60 degree temps really do feel good !
I'm really happy with the forecast we put out Friday for this weekend - sky conditions, temps, precip patterns ... you name it, everything worked out just about perfectly.
Alright let's get to the weather at hand and what is heading our way.
Big storm system currently located across the upper midwest will continue to push rapidly northeast this afternoon into tonight. H7 dryslot is currently overspreading the Ohio Valley with some subsidence behind initial wave of showers. Should see a few breaks in the overcast this afternoon allowing for peeks of sunshine. LLJ continues to crank over the region and with a well mixed atmosphere, sfc winds will stay very gusty. Wind gusts could easily reach 45 mph and be as high as 50 mph!
Diff. PVA and sfc cold front will likely bring scattered showers back into the region later this afternoon into the evening. Instability is very limited however and will likely continue to drop off as somewhat of a dry line surges across the region this afternoon dropping the dew points from the 50s back into the 40s.
Cold front moves through tonight with strong CAA into the region. 6 hour pressure rises suggest winds will stay very gusty this evening with gusts still as high as 40 mph. Upper trough sets up over the region later tonight through Tuesday morning. As low level (H9 - H8) temps continue to drop into the ice crystal generation regions, flurries will become likely as Monday wears on. Monday evenin / night, a vort lobes passing through the upper trough and H85 temps in the dentrite growth region at a time of nearly saturation would suggest an enhancement in the flurries with even some brief heavier snow showers possible. No, not a big snowmaker but certainly a dusting / less than 1 inch possible in areas.
We should see lots of sun Tuesday afternoon as upper jet axis shifts east of the region.
Another strong shortwave will translate through the trough Tuesday night into Wednesday morning (it will stay well north of us but its attending cold front will drift south over the region on Wednesday. Air behind the boundary is polar / arctic in nature as a 1040 high drifts south from Canada towards the Great Lakes and the Upper Ohio Valley.
After this cold air mass moves through, the upper pattern cahnges out west suggest a DEamplification process will be under way. Strong Pacific jet will beat down western ridge cutting off the cold air.
Overall, temperatures will begin a warmup as we go back to average or even above average through next weekend into the beginning of the following week
As pattern shifts back to the warmer setup, a couple of fast moving shortwaves will ride the jet stream towards the Mississippi Valley and the Ohio Valley. These shorts will enhance the WAA pattern over the area resulting in shower chances for later on Friday and Saturday.
Have a great Sunday and President's Day
Later: Jay
I'm really happy with the forecast we put out Friday for this weekend - sky conditions, temps, precip patterns ... you name it, everything worked out just about perfectly.
Alright let's get to the weather at hand and what is heading our way.
Big storm system currently located across the upper midwest will continue to push rapidly northeast this afternoon into tonight. H7 dryslot is currently overspreading the Ohio Valley with some subsidence behind initial wave of showers. Should see a few breaks in the overcast this afternoon allowing for peeks of sunshine. LLJ continues to crank over the region and with a well mixed atmosphere, sfc winds will stay very gusty. Wind gusts could easily reach 45 mph and be as high as 50 mph!
Diff. PVA and sfc cold front will likely bring scattered showers back into the region later this afternoon into the evening. Instability is very limited however and will likely continue to drop off as somewhat of a dry line surges across the region this afternoon dropping the dew points from the 50s back into the 40s.
Cold front moves through tonight with strong CAA into the region. 6 hour pressure rises suggest winds will stay very gusty this evening with gusts still as high as 40 mph. Upper trough sets up over the region later tonight through Tuesday morning. As low level (H9 - H8) temps continue to drop into the ice crystal generation regions, flurries will become likely as Monday wears on. Monday evenin / night, a vort lobes passing through the upper trough and H85 temps in the dentrite growth region at a time of nearly saturation would suggest an enhancement in the flurries with even some brief heavier snow showers possible. No, not a big snowmaker but certainly a dusting / less than 1 inch possible in areas.
We should see lots of sun Tuesday afternoon as upper jet axis shifts east of the region.
Another strong shortwave will translate through the trough Tuesday night into Wednesday morning (it will stay well north of us but its attending cold front will drift south over the region on Wednesday. Air behind the boundary is polar / arctic in nature as a 1040 high drifts south from Canada towards the Great Lakes and the Upper Ohio Valley.
After this cold air mass moves through, the upper pattern cahnges out west suggest a DEamplification process will be under way. Strong Pacific jet will beat down western ridge cutting off the cold air.
Overall, temperatures will begin a warmup as we go back to average or even above average through next weekend into the beginning of the following week
As pattern shifts back to the warmer setup, a couple of fast moving shortwaves will ride the jet stream towards the Mississippi Valley and the Ohio Valley. These shorts will enhance the WAA pattern over the area resulting in shower chances for later on Friday and Saturday.
Have a great Sunday and President's Day
Later: Jay
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