weatherwiz Posted May 22, 2011 Share Posted May 22, 2011 After a week of cut-off hell with miserable May weather things finally began improving on Saturday and this will continue throughout the next several days, however, around mid-week there may be a day or two of poor weather but it shouldn't be anything like the days we saw last week. As far as Tuesday goes during the morning hours a s/w will be passing overhead and with increasing low-level moisture and some elevated instability this s/w may spark off a few showers and t'storms. What happens behind this s/w will be key. It appears there will be some subsidence in the wake of the s/w which should help us out some as this along with heating should help to burn off any clouds overhead allowing for a period of much stronger sfc heating. With 925mb temps nearing +20C and 850mb temps nearing +15C and a good deal of mixing this would promote highs well into the mid 80's away from the coast, due to some cloud cover issues, early on at least we probably won't reach full potential as far as temperatures goes but we should be anywhere from the mid 70's to lower 80's across the region. Dewpoints will creep up there as well getting well into the lower 60's. With mid-level temperatures still rather on the cool side (around -13C or so) this should make way for some fairly steep lapse rates, probably around 6.5 C/KM or so. Given the potential for temperatures to make it to 80F or higher and dewpoints into the lower 60's this should create some modest instability values. How unstable we become will all depend on how warm the sfc temperatures get as well as high high the dewpoints are. As far as win shear goes it really isn't overly impressive as the strongest low-level winds move off-shore during the morning hours ans the strongest mid-level winds remain just off-shore. However, with a cold front approaching from the west mid-level winds should once again be on the increase during the afternoon hours. This should yield to around 30-35 knots of vertical shear which should be just enough to help for some sort of storm organization. Parts of the region may also be in the LFQ of the ULJ which may help to enhance upward motion. With any thunderstorms the main threat right now appears to be torrential downpours are PWATS are pretty high, up around 1.5''. Depending on the degree of instability there could be a threat for a few severe storms and large hail/damaging winds would then also be possible. The lift will be generated by a cold front which will be moving eastward during the morning/afternoon hours. Some of the keys for Tuesday will be how unstable we can become and whether or not the subsidence is too strong to overcome. Looks like a wave of low pressure also develops along the front and this will help to make the front stall just south of the region making for much cooler on Wednesday and for periods of showers, some heavy at times. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 22, 2011 Author Share Posted May 22, 2011 Still looking a little interesting on Tuesday if we can overcome that s/w subsidence and end up destabilizing enough. One thing that could be a killer though, especially with allowing for more instability is weakening lapse rates as the day goes on. Link to comment Share on other sites More sharing options...
CT Rain Posted May 22, 2011 Share Posted May 22, 2011 Still looking a little interesting on Tuesday if we can overcome that s/w subsidence and end up destabilizing enough. One thing that could be a killer though, especially with allowing for more instability is weakening lapse rates as the day goes on. Wind fields are pretty weak. Not much shear. Looks sort of crappy to be honest. We could see a scattered SVR warnings with marginal (probably exaggerated) reports. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 22, 2011 Author Share Posted May 22, 2011 Wind fields are pretty weak. Not much shear. Looks sort of crappy to be honest. We could see a scattered SVR warnings with marginal (probably exaggerated) reports. The wind fields due weaken as the day goes on which blows. This is not going to be a widespread severe producing event but if we can develop some decent instability we should actually finally get a few severe reports...some hail and some wind. Link to comment Share on other sites More sharing options...
weatherMA Posted May 22, 2011 Share Posted May 22, 2011 I think I've seen one severe storm in my life. lol Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 We'll have to see what happens as we continue to get closer to Tuesday. This is not going to be a widespread severe wx event but there should be some strong to marginally severe storms around the entire region. A couple things of interest to note with tonight's 0z/23 model suite. First, the NAM develops an area of low pressure, right along the front it appears and it actually intensifies some and this is noted by a very impressive vort max at 500mb. Out ahead of this feature winds aloft actually increase and by a good amount. Talking at 30-50 knots for the LLJ, 40-60 knots for the MLJ, and the area gets into the RRQ of a modest 50-60 kt ULJ. The ML lapse rates continue to be modest, right around 6 C/KM...this isn't overly bad but they could obviously be better. The GFS is completely different as it does NOT develop this feature so wind fields on the GFS are very, very weak. Like the NAM though it does develop some decent instability across portions of the region as temperatures will have the potential to get into the 80's away from the coast with dewpoints into the lower 60's. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 Slight Risk for parts of CT!!!!! ...NORTHERN MID ATLANTIC STATES INTO THE LOWER HUDSON VALLEY... WEAK TO MODERATE DESTABILIZATION ALONG AND AHEAD OF THE SOUTHEASTWARD ADVANCING COLD FRONT...AND WITHIN THE PRE-FRONTAL LEE SURFACE TROUGH...IS EXPECTED TO PROVIDE THE FOCUS FOR VIGOROUS CONVECTIVE DEVELOPMENT WITH THE APPROACHING UPPER IMPULSE TUESDAY AFTERNOON. MODELS ARE A BIT MORE UNCLEAR CONCERNING THE STRENGTH OF THE VERTICAL SHEAR...BUT IT SHOULD BE ENOUGH TO SUPPORT POTENTIAL FOR ORGANIZED STORM CLUSTERS...AND ISOLATED SUPERCELLS MAY NOT BE OUT OF THE QUESTION. THIS COULD IMPACT MUCH OF THE URBAN CORRIDOR...FROM WASHINGTON D.C./BALTIMORE TO NEW YORK CITY...BEFORE CONVECTION DIMINISHING/SPREADS OFFSHORE WITH UPPER FORCING BY TUESDAY EVENING. Link to comment Share on other sites More sharing options...
TalcottWx Posted May 23, 2011 Share Posted May 23, 2011 I think this will be a pretty decent event by SNE standards.. some shear.. some instability.. some steep lapse rates.. sufficient heating. and good ssw flow.. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 I think this will be a pretty decent event by SNE standards.. some shear.. some instability.. some steep lapse rates.. sufficient heating. and good ssw flow.. I think we'll see a few strong to severe storms across parts of SNE, however it will likely be the interior. With a S/SW sfc flow that's going to scream marine airmass for those near the coasts. The better severe threat may exist just off to our south/west, especially if the mesoscale models are onto that idea of the very potent s/w. However, if they are correct with that feature it's accompanied by a pool of warmer air aloft which would locally kill lapse rates thus decreasing instability. Link to comment Share on other sites More sharing options...
TalcottWx Posted May 23, 2011 Share Posted May 23, 2011 SPC says isolated supercells and organized storm clusters in the slight risk region.. It will be at least fun to watch on Tuesday. The best supercell related indices actually look to be over interior sne because of the s/w departing... I don't see much of anything organized due to lack of strong shear Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 SPC says isolated supercells and organized storm clusters in the slight risk region.. It will be at least fun to watch on Tuesday. The best supercell related indices actually look to be over interior sne because of the s/w departing... I would think it would be just off to our west (or SW) as this is where the better shear would be juxtaposed with the potential stronger instability. Plus given the sfc wind direction and low-level wind direction the southern end of the Hudson Valley would be ideal as winds would be further backed here. Plus, with regards to the pre-frontal trough I've found when LL winds are greater than 30-35 knots they tend to back more around the pre-frontal trough, but this is also dependent on the level of directional shear in the lowest 2 KM. Link to comment Share on other sites More sharing options...
TalcottWx Posted May 23, 2011 Share Posted May 23, 2011 WHILE MUCH OF TUESDAY WILL BE DRY...THE POTENTIAL FOR SCATTERED SHOWERS AND THUNDERSTORMS WILL EXIST DURING THE AFTERNOON/EVENING AS A COLD FRONT/PRE-FRONTAL TROUGH DROPS INTO THE REGION. THINGS ARE NOT EXACTLY CLEAR CUT ON THE CONVECTIVE POTENTIAL AND WILL LIKELY HAVE TO SEE WHAT HAPPENS WITH TONIGHT/S ACTIVITY FIRST TO HAVE A BETTER HANDLE ON IT. HOWEVER...THERE IS THE POTENTIAL FOR A FEW SEVERE THUNDERSTORMS MAINLY TO THE NORTHWEST OF A BOSTON TO PROVIDENCE LINE. THE PRIMARY RISK WOULD BE FOR LARGE HAIL AND STRONG DAMAGING STRAIGHT LINE WIND GUSTS WITH ANY SEVERE THUNDERSTORM. ALSO...PWATS AROUND 1.5 INCHES WILL BRING THE POTENTIAL FOR LOCALLY HEAVY RAINFALL WITH ANY THUNDERSTORM. AGAIN...A LOT OF UNCERTAINTY REVOLVES AROUND WHERE THIS ACTIVITY INITIATES AND THE EXTENT OF ITS AREAL COVERAGE. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 Just like earthlight mentioned in the NYC thread...gotta take this with extreme caution b/c if this s/w doesn't pan out this is nothing more than just an isolated severe threat. Regardless though for our region that's what this will likely be, although extreme western CT could see something bigger. We'll have to see what the 12z NAM shows. Actually could see if the 6z NAM holds firm with this. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 Yup...6z NAM much flatter and not as potent with this feature. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 The 3z SPC SREF does NOT like SNE tomorrow Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 The 6z NAM though is pretty darn unstable on Tuesday with modest lapse rates that due weaken late in the afternoon. Though it might be a tad overdone with sfc dewpoints. Link to comment Share on other sites More sharing options...
weathafella Posted May 23, 2011 Share Posted May 23, 2011 I've lived in the NYC area and lived in SNE. They must get 5x what we get in terms of severe. Don't compare. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted May 23, 2011 Share Posted May 23, 2011 Tomorrow is a 100% PHAIL for SNE. Setup is not right at all for anything Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 Tomorrow is a 100% PHAIL for SNE. Setup is not right at all for anything Oh Link to comment Share on other sites More sharing options...
weathafella Posted May 23, 2011 Share Posted May 23, 2011 Oh I suspect I'll see something in KC Wednesday....hopefully after I'm on the ground. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 I suspect I'll see something in KC Wednesday....hopefully after I'm on the ground. IDK...Tuesday's probably going to be the better day for that area, looks like the storm system will be eat of there come Wednesday. Looks like you miss out by one day Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 Ohh...you said KC...thought that saidt KS...yeah you may see something in MO on Wednesday, I'm assuming you'll be on the MO side? Link to comment Share on other sites More sharing options...
weathafella Posted May 23, 2011 Share Posted May 23, 2011 Ohh...you said KC...thought that saidt KS...yeah you may see something in MO on Wednesday, I'm assuming you'll be on the MO side? Yep...MCI Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 Yep...MCI Too bad you won't be out there on Tuesday, looks like another large outbreak of severe wx...hopefully the same areas that got pounded yesterday get hit again. That's been one of the worst parts of this season, the same areas just keep getting hit again and again. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 Besides the other normal issues I wonder if we'll have MAJOR issues overcoming s/w subsidence from the morning s/w? Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 The 9z SPC SREF completely blows for tomorrow. Link to comment Share on other sites More sharing options...
CT Rain Posted May 23, 2011 Share Posted May 23, 2011 BTW the difference in instability between the 6z GFS and 6z NAM is laughable for tomorrow. GFS has like 400 j/kg of SBCAPE at BDL while the NAM has 2400 j/kg lol NAM dew point forecast FAIL Link to comment Share on other sites More sharing options...
Damage In Tolland Posted May 23, 2011 Share Posted May 23, 2011 It's over before it even began..Pull your plug now instead of holding out hope Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 BTW the difference in instability between the 6z GFS and 6z NAM is laughable for tomorrow. GFS has like 400 j/kg of SBCAPE at BDL while the NAM has 2400 j/kg lol NAM dew point forecast FAIL Yeah that 2400 was not happening...I was thinking more along the lines of 1250-1500 J/kG at most. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 23, 2011 Author Share Posted May 23, 2011 Now I can look towards Friday. Link to comment Share on other sites More sharing options...
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