NaoPos Posted April 23, 2011 Share Posted April 23, 2011 looks to be an active period this week, starting with tomorrow's outlook by the SPC: SPC AC 230558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT SAT APR 23 2011 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID-ATLANTIC REGION WSWWD ACROSS THE OH AND MID MS VALLEYS INTO THE SRN PLAINS... ...SYNOPSIS... LARGE-SCALE UPPER TROUGH OVER THE WRN U.S. WILL SHIFT SLOWLY EWD WITH TIME...AFFECTING THE CENTRAL U.S. AS HEIGHTS FALL ACROSS THIS REGION. AT THE SURFACE...A FRONT WILL LINGER/REMAIN ROUGHLY STATIONARY FROM THE MID-ATLANTIC REGION WSWWD INTO THE SRN PLAINS...AND AS THE UPPER TROUGH ADVANCES...THIS FRONT -- PARTICULARLY OVER THE S CENTRAL U.S. -- WILL BE A FOCUS FOR FAIRLY WIDESPREAD SEVERE WEATHER POTENTIAL. ...TX/OK/WRN AR... STORMS ARE LIKELY TO BE ONGOING ACROSS PARTS OF OK AND AR AT THE START OF THE PERIOD...NEAR AND N OF THE FRONTAL ZONE. FARTHER S...MOIST BOUNDARY LAYER SUBJECT TO AFTERNOON HEATING WILL BECOME MODERATELY UNSTABLE -- THOUGH CAPPING SHOULD INHIBIT DEVELOPMENT INITIALLY. HOWEVER...AS THE UPPER TROUGH ADVANCES SLOWLY EWD...PERSISTENT UVV -- FOCUSED NEAR AND N OF THE SURFACE FRONT AND ALONG A DRYLINE MIXING EWD ACROSS THE TRANSPECOS REGION -- SHOULD SUPPORT STORM DEVELOPMENT DURING THE AFTERNOON ACROSS A LARGE PORTION OF CENTRAL TX AND INTO OK/AR. ALONG WITH FAVORABLE INSTABILITY...LOW-LEVEL SLYS VEERING TO WSWLY AT 50 KT AT MID-LEVELS WILL RESULT IN SHEAR SUPPORTIVE OF SUPERCELLS. AS STORMS ACQUIRE ROTATION SHORTLY AFTER DEVELOPMENT...THREAT FOR VERY LARGE HAIL APPEARS LIKELY WITH SCATTERED/STRONGER STORMS...ALONG WITH THREATS FOR LOCALLY-DAMAGING WINDS AS WELL AS A COUPLE OF TORNADOES. WHILE STORMS SHOULD CONTINUE ACROSS TX INTO THE EVENING...MORE WIDESPREAD STORMS SHOULD DEVELOP -- AND CONTINUE THROUGH THE PERIOD -- FARTHER N...NEAR AND N OF THE SURFACE FRONT AS A SLY LOW-LEVEL JET REDEVELOPS. A THREAT FOR ELEVATED STORMS CAPABLE OF PRODUCING LARGE HAIL WILL EXPAND NEWD OVERNIGHT -- INCLUDING PORTIONS OF SERN KS AND SRN MO THROUGH 25/12Z. ...MID-ATLANTIC REGION SWWD ACROSS THE OH AND MID MS VALLEYS... SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING INVOF THE FRONT AT THE START OF THE PERIOD...WITH CONVECTION LIKELY TO PERSIST/INCREASE IN BOTH COVERAGE AND INTENSITY THROUGH THE AFTERNOON AS LOCAL HEATING/DESTABILIZATION OCCURS. WHILE MODERATELY-STRONG WSWLYS ALOFT WILL BE SUFFICIENT FOR STORM ORGANIZATION/LONGEVITY...THE FLOW PARALLEL TO THE BOUNDARY IS NOT IDEAL IN TERMS OF SEVERE THREAT. WHILE THIS COMBINED WITH THE PERSISTENT CONVECTION AND ASSOCIATED CLOUD COVER SHOULD HINDER THE OVERALL THREAT...POTENTIAL FOR DAMAGING WINDS AND HAIL APPEARS SUFFICIENT -- PARTICULARLY GIVEN THE POSSIBILITY OF MORE THAN ONE CONVECTIVE EPISODE IN MANY LOCATIONS -- TO SUPPORT UPGRADE TO SLIGHT RISK ALONG THE LENGTH OF THE FRONT. ..GOSS.. 04/23/2011 Discuss Link to comment Share on other sites More sharing options...
Thunder Road Posted April 23, 2011 Share Posted April 23, 2011 Going off the 6z GFS (which might be a poor choice, who knows) it looks like the real deal is Thursday. Look at that FROPA at 138! Overall looks like a good week for Lee with a chance of storms almost every day but Tuesday Link to comment Share on other sites More sharing options...
Thunder Road Posted April 23, 2011 Share Posted April 23, 2011 Bri, do you wanna change the title to make this the thread for next week's warmth/storms too, or keep them in separate threads? Link to comment Share on other sites More sharing options...
NaoPos Posted April 23, 2011 Author Share Posted April 23, 2011 We'll just discuss tomorrow for now. Seems like we'll have a break in between threats. Once tomorrow evening rolls around, ill change the thread for later in the week. fair deal? Link to comment Share on other sites More sharing options...
Thunder Road Posted April 23, 2011 Share Posted April 23, 2011 We'll just discuss tomorrow for now. Seems like we'll have a break in between threats. Once tomorrow evening rolls around, ill change the thread for later in the week. fair deal? Works for me. Link to comment Share on other sites More sharing options...
LVblizzard Posted April 23, 2011 Share Posted April 23, 2011 12z SPC WRF valid 6pm tomorrow: Link to comment Share on other sites More sharing options...
phlwx Posted April 23, 2011 Share Posted April 23, 2011 18z NAM is active after 2 PM...best threat seems to be between Philly and I-78. Link to comment Share on other sites More sharing options...
NaoPos Posted April 23, 2011 Author Share Posted April 23, 2011 From mt holly: NO CHANGE IN THE MODELING PREMISE FOR SUNDAY INTO MONDAY WITH THE COLD FRONT SAGGING SOUTH, STALLING AND THEN DRIFTING NORTHWARD ON MONDAY. THE CONVECTIVE POTENTIAL ON SUNDAY LOOKS STRONGEST OF THE THREE DAYS BASED ON SUFFICIENT DAYTIME HEATING AND SOME DEW POINT POOLING BECAUSE OF THE FRONTAL BOUNDARY. SPC HAS KEPT A CHUNK OF OUR CWA IN SLIGHT RISK FOR SEVERE TSRAS. THERE IS NO DENYING FCST BULK SHEAR VALUES ARE SUFFICIENT AS ARE ENERGETIC FCST MID LEVEL LAPSE RATES. MODEL FCST DEW POINTS (AS HIGH AS THE MID 60S) ARE NOT OVERTLY TOO BULLISH AS THEY LOOK ON MONDAY AND TUESDAY. NOT GOING TO ADD ENHANCED WORDING FOR NOW AS ARE CONCERNED ABOUT THE EXTENT OF DEW POINT POOLING TO REACH THOSE NEEDED MID 60S. WE WILL CONTINUE MENTION IN THE HWO. THE HI RES MODELS FAVOR THE GREATEST CONVECTIVE PUNCH AROUND 21Z (THEY NORMALLY ARE A COUPLE OF HOURS TOO SLOW) IN THE PHL NORTHERN AND WESTERN SUBURBS. AS FAR AS FOCUS OVERALL WE LIKE CENTRAL AND SOUTH BETTER THAN NORTH BASED ON THE LOCATION OF THE FCST LLVL THETA E RDG AND THE 300K FCST ISENTROPIC MOISTURE TRANSPORT AXIS. THE BEST OUTFLOW FROM THE H2.5 JET IS NORTH AS IN NY AND NEW Link to comment Share on other sites More sharing options...
Thunder Road Posted April 24, 2011 Share Posted April 24, 2011 0z NAM has showers around tomorrow afternoon, but nothing too heavy. Instability is also rather limited to south central PA. It has great instability (~1500 J/Kg CAPE) for Monday though, and a rather nice line moving through between 0z and 3z Tue. Link to comment Share on other sites More sharing options...
Thunder Road Posted April 24, 2011 Share Posted April 24, 2011 porn from the 0z SPC WRF Helicity & VIL don't look too shabby either. I like how this lines up with the axis of better instability, rather than before where it had storms where there was no CAPE and no storms where there was CAPE Link to comment Share on other sites More sharing options...
SmokeEater Posted April 24, 2011 Share Posted April 24, 2011 porn from the 0z SPC WRF Helicity & VIL don't look too shabby either. I like how this lines up with the axis of better instability, rather than before where it had storms where there was no CAPE and no storms where there was CAPE That tomorrow? Or Monday? Link to comment Share on other sites More sharing options...
NaoPos Posted April 24, 2011 Author Share Posted April 24, 2011 porn from the 0z SPC WRF Helicity & VIL don't look too shabby either. I like how this lines up with the axis of better instability, rather than before where it had storms where there was no CAPE and no storms where there was CAPE Looks like this ehh? Link to comment Share on other sites More sharing options...
NaoPos Posted April 24, 2011 Author Share Posted April 24, 2011 or this? same day, 2 diff scans: Link to comment Share on other sites More sharing options...
Thunder Road Posted April 24, 2011 Share Posted April 24, 2011 Oh don't bring up 6/24/10. That was an awful miss for me. I recorded a Mr. Blutarsky while everyone to my south got hit, and somehow Lee still found a way to complain about not getting enough lightning. Link to comment Share on other sites More sharing options...
Thunder Road Posted April 24, 2011 Share Posted April 24, 2011 Anyway, back to today... 07z HRRR has a broken line of storms hitting Baltimore & DC a little after 22z, with decent SBCAPE of around 1500 to 2000 (although idk if the HRRR overdoes CAPE like the RUC does) Link to comment Share on other sites More sharing options...
Thunder Road Posted April 24, 2011 Share Posted April 24, 2011 08z HRRR valid for 23z today Link to comment Share on other sites More sharing options...
phlwx Posted April 24, 2011 Share Posted April 24, 2011 Looking at radar and where things are at...I'd guess the best shot is after 2 north/west of city, after 4 in Philly/north. The stuff in WV now might foul that up though if it hangs on. Hoping things stay clear for a few hours...not just for severe prospects but also for warmth. Link to comment Share on other sites More sharing options...
Parsley Posted April 24, 2011 Share Posted April 24, 2011 Upper 60s here this morning with some sun already......nice start to Easter. Link to comment Share on other sites More sharing options...
Thunder Road Posted April 24, 2011 Share Posted April 24, 2011 plenty warm here already, 66.8°/63 Link to comment Share on other sites More sharing options...
ParanormalWx Posted April 24, 2011 Share Posted April 24, 2011 Looking at radar and where things are at...I'd guess the best shot is after 2 north/west of city, after 4 in Philly/north. The stuff in WV now might foul that up though if it hangs on. Hoping things stay clear for a few hours...not just for severe prospects but also for warmth. I just saw that stuff coming into SW PA...5-6 hours away, if it holds together. Link to comment Share on other sites More sharing options...
Thunder Road Posted April 24, 2011 Share Posted April 24, 2011 ok, last one I swear seriously though, very nice signal from the hi-res models that we get some good stuff this afternoon. and encouraging that it's already sunny. let's see how long it holds. Link to comment Share on other sites More sharing options...
LVblizzard Posted April 24, 2011 Share Posted April 24, 2011 65F and mostly sunny! Excellent weather for Easter! It would be even better if we could get some storms later today. Link to comment Share on other sites More sharing options...
chubbs Posted April 24, 2011 Share Posted April 24, 2011 68F - Should be mostly sunny all morning. Could be an active PM Link to comment Share on other sites More sharing options...
Thunder Road Posted April 24, 2011 Share Posted April 24, 2011 69.5° with high cirrus moving in, we might bit 70 before 10am! hopefully we get some :mapstorm: this afternoon Link to comment Share on other sites More sharing options...
phlwx Posted April 24, 2011 Share Posted April 24, 2011 PTW 73 at 10 AM....very good sign for some strong storms later. Want to see what develops once those showers dump down off of the mountains in the next hour or two. Link to comment Share on other sites More sharing options...
NaoPos Posted April 24, 2011 Author Share Posted April 24, 2011 Pockets of instability with sb cape around 1000 creeping into se pa. . Would like to see some to our west. Mid level lapse rates rising nicely to around 6.5 at this hour. Link to comment Share on other sites More sharing options...
LVblizzard Posted April 24, 2011 Share Posted April 24, 2011 Mostly clear here, mostly cloudy to my north. The deck of clouds is really close to the SPC slight risk northern border. Edit: Clouds are moving in from the west...based on the satellte they should cover a good part of the region for awhile. Link to comment Share on other sites More sharing options...
Big Jims Videos Posted April 24, 2011 Share Posted April 24, 2011 It's tropical at the jersey shore about 80 in wall right now I'm shirtless on the deck getting a shore tan . Not a cloud to be found Link to comment Share on other sites More sharing options...
atownwxwatcher Posted April 24, 2011 Share Posted April 24, 2011 MESOSCALE DISCUSSION 0549 NWS STORM PREDICTION CENTER NORMAN OK 0112 PM CDT SUN APR 24 2011 AREAS AFFECTED...SERN PA...NJ...DE...MD...NRN VA...WASHINGTON DC CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 241812Z - 241945Z PORTIONS OF SERN PA...NJ...DE...MD...NRN VA...AND WASHINGTON DC ARE BEING MONITORED FOR THUNDERSTORM INITIATION AND SUBSEQUENT INCREASE IN SVR WEATHER POTENTIAL/POSSIBLE WW ISSUANCE THIS AFTERNOON. MESOANALYSIS INDICATES A COLD FRONT WAS LOCATED FROM SERN NY WSW ACROSS CNTRL/SRN PA AND INTO THE OH VALLEY REGION AT 18Z. TEMPERATURES S OF THE FRONT ARE WARMING INTO THE 70S AND 80S...WHICH IS AIDING IN STEEPENING LOW-LEVEL LAPSE RATES AND BOUNDARY LAYER DESTABILIZATION. IN ADDITION...AXIS OF LOW 60S DEWPOINTS EXTENDS NWD INTO THE MID ATLANTIC REGION...WHICH IS AIDING IN WEAK TO MODERATE INSTABILITY...WITH MLCAPE VALUES EXPECTED TO PEAK AROUND 500-1500 J/KG DURING THE AFTERNOON. THOUGH UPPER-LEVEL SUPPORT FOR ADDITIONAL AIRMASS DESTABILIZATION IS GENERALLY LACKING...COMBINATION OF CONTINUED SURFACE HEATING...CONVERGENCE/ASCENT ALONG THE COLD FRONT...AND VERTICAL MOTION FIELDS ASSOCIATED WITH APPROACHING MCV OVER SERN OH/NRN WV MAY AID IN THUNDERSTORM INITIATION DURING THE NEXT FEW HOURS. VWP WIND PROFILES AND RUC FORECAST SOUNDINGS INDICATE THAT VERTICAL WIND SHEAR IS FAVORABLE FOR BOTH SUPERCELLS AND FAST MOVING LINE SEGMENTS. THE PRIMARY THREAT ASSOCIATED WITH ANY SVR STORM ACTIVITY WILL LIKELY BE DAMAGING WINDS...THOUGH ISOLATED LARGE HAIL AND A TORNADO CANNOT BE RULED OUT. Link to comment Share on other sites More sharing options...
Thunder Road Posted April 24, 2011 Share Posted April 24, 2011 81.8°/63 much warmer than expected It has that thunderstormy look out there with all the cumulus bubbling up, and haze around it all Link to comment Share on other sites More sharing options...
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