Saturday, May 21, 2016
Post date: May 21, 2016 2:07:22 PM
Saturday, May 21, 2016 @ 0800 MDT: Yesterday we shifted slightly farther north, ending up in Lamar, CO. The group did laundry, hit Wally World, charged camera and camcorder batteries and did everything else in preparation for a series of days of (hopefully) great storm chasing! Then, after dinner, many of us got together to toast our missing compadres... Chris Curtis and Brad Riley. We miss you guys!!!
So it's looking like today should be a very interesting chase day in western Kansas. I have included the SPC forecast below, for any of you who are interested in the details, but the bottom line is that we are in far eastern Colorado now, so we shouldn't have to move very far to be in good position for the storms!
I have uploaded a few shots from our day yesterday, and you can see them HERE: https://kingkey.smugmug.com/TornadoChase/Chase-2016/2016May20/
Keep up with my latest updates on Twitter, which you can see by going to https://twitter.com/StickerThad.
SPC AC 211250
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0750 AM CDT SAT MAY 21 2016
VALID 211300Z - 221200Z
...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING ACROSS CENTRAL/ERN MT...
...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FROM WRN KS TO THE TX PANHANDLE...
...THERE IS A MRGL RISK OF SVR TSTMS THROUGH TONIGHT THE HIGH PLAINS FROM WEST TX TO WY AND THE WRN DAKOTAS...
...THERE IS A MRGL RISK OF SVR TSTMS THIS AFTERNOON FROM THE CAROLINAS TO THE FL E COAST...
...THERE IS A MRGL RISK OF SVR TSTMS TODAY ACROSS THE MIDDLE TX COASTAL PLAIN...
...SUMMARY...
A FEW DAMAGING GUSTS AND LARGE HAIL ARE EXPECTED THIS AFTERNOON/EVENING ACROSS CENTRAL AND EASTERN MONTANA. A SEPARATE AREA OF SEVERE STORMS IS ALSO EXPECTED FROM WESTERN KANSAS TO WEST CENTRAL TEXAS... WHERE LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE. A COUPLE OF TORNADOES MAY ALSO OCCUR THIS AFTERNOON/EVENING IN WESTERN KANSAS.
...MT AREA THIS AFTERNOON/EVENING...
A CLOSED LOW OVER NRN CA/NV/ORE WILL PROGRESS TOWARD THE NRN ROCKIES AS AN EMBEDDED SPEED MAX ROTATES NNEWD FROM SRN NV TO UT/WY. THE LEFT EXIT REGION OF THE MID-UPPER JET WILL OVERSPREAD PARTS OF THE NRN ROCKIES TO CENTRAL MT THROUGH THIS AFTERNOON... WHERE LARGE-SCALE ASCENT WILL BE AUGMENTED ALONG A N-S BAROCLINIC ZONE ACROSS CENTRAL MT. CLUSTERS OF THUNDERSTORMS AND LINE SEGMENTS ARE EXPECTED TO DEVELOP ALONG THE BAROCLINIC ZONE THIS AFTERNOON AND SPREAD NNEWD THROUGH THIS EVENING. SURFACE HEATING IN CLOUD BREAKS E OF THE FRONT... COMBINED WITH BOUNDARY LAYER DEWPOINTS IN THE LOW-MID 50S... WILL SUPPORT AFTERNOON MLCAPE VALUES OF 500-1000 J/KG. ADDITIONALLY... INCREASING DEEP-LAYER SLY SHEAR WILL SUPPORT ORGANIZED BOWING SEGMENTS AND THE POTENTIAL FOR EMBEDDED SUPERCELLS CAPABLE OF PRODUCING DAMAGING GUSTS AND LARGE HAIL.
...WRN KS TO THE TX PANHANDLE THIS AFTERNOON INTO TONIGHT...
SLY LOW-LEVEL FLOW... IN RESPONSE TO LEE CYCLOGENESIS ACROSS THE NRN/CENTRAL HIGH PLAINS... WILL TRANSPORT BOUNDARY LAYER DEWPOINTS IN THE LOW-MID 60S NWD FROM NW TX TOWARD WRN KS. PERSISTENT LOW CLOUDS ACROSS PARTS OF NW KS AND SW NEB SHOULD RESULT IN DIFFERENTIAL HEATING ZONE/WARM FRONT FORMATION TODAY... WITH STRONGER SURFACE HEATING EXPECTED S-SW OF THIS BOUNDARY ACROSS WRN KS. AFTERNOON MLCAPE VALUES COULD APPROACH 2000 J/KG AS SURFACE TEMPERATURES WARM INTO THE 75-80 F RANGE E OF THE DEVELOPING HIGH PLAINS DRYLINE... AND S OF THE DIFFERENTIAL HEATING ZONE. THUNDERSTORM DEVELOPMENT IS EXPECTED LATE AFTERNOON ALONG THE DRYLINE AND UP TO THE TRIPLE POINT INTO NW KS.
DEEP-LAYER VERTICAL SHEAR WILL BECOME MARGINALLY FAVORABLE FOR SUPERCELLS AS THE MIDLEVEL RIDGE SPREADS E OF THE HIGH PLAINS BY AFTERNOON. LOW-LEVEL SHEAR WILL BE STRONGER ALONG AND N OF THE WARM FRONT... AND LATER THIS EVENING AS LOW-LEVEL WINDS BEGIN TO STRENGTHEN IN THE WARM SECTOR. STORM LONGEVITY COULD BE LIMITED SOME BY OUTFLOW GENERATION RELATED TO RELATIVELY WEAK MID-UPPER FLOW... BUT THERE SHOULD STILL BE A FEW HOUR WINDOW OF OPPORTUNITY FOR SLOW-MOVING SUPERCELLS LATE AFTERNOON/EVENING. LARGE HAIL AND DAMAGING OUTFLOW GUSTS CAN BE EXPECTED... WHILE LOW-LEVEL SHEAR AND MOISTURE SHOULD BE SUFFICIENT FOR A COUPLE OF TORNADOES.
FARTHER S INTO THE TX PANHANDLE AND W CENTRAL TX... SCATTERED THUNDERSTORMS SHOULD ALSO FORM ALONG THE DRYLINE BY MID-LATE AFTERNOON. MODERATE BUOYANCY /MLCAPE 1500-2000 J PER KG/ AND EFFECTIVE BULK SHEAR AROUND 30 KT WILL SUPPORT A MIX OF ORGANIZED MULTICELL CLUSTERS AND MARGINAL SUPERCELL STORMS... WITH AN ATTENDANT RISK FOR LARGE HAIL/DAMAGING WINDS. SOME CONVECTION COULD PERSIST OVERNIGHT INTO NW TX IN ASSOCIATION WITH INCREASING LOW-LEVEL MOISTURE AND WAA... BUT CONFIDENCE IN THE DETAILS OF THIS CONVECTIVE EVOLUTION ARE LOW.
...SE STATES THIS AFTERNOON...
A MIDLEVEL TROUGH WILL ROTATE GENERALLY EWD FROM THE SRN APPALACHIANS AS CYCLOGENESIS OCCURS OFF THE NC COAST. LINGERING LOW-LEVEL MOISTURE AND SURFACE HEATING IN CLOUD BREAKS WILL SUPPORT WEAK-MODERATE BUOYANCY THIS AFTERNOON... IN AN ENVIRONMENT WITH 30-40 KT DEEP-LAYER SHEAR. A FEW STORMS THIS AFTERNOON COULD PRODUCE ISOLATED STRONG/DAMAGING WINDS... AS WELL AS SMALL HAIL. FARTHER S... A FEW STRONG STORMS ARE EXPECTED ALONG THE FL E COAST SEA BREEZE.
...MIDDLE TX COAST TODAY...
SLIGHTLY ELEVATED CONVECTION IS ONGOING IN A ZONE OF LOW-LEVEL WAA... AND RADAR HAS SHOWN EVIDENCE OF SOME STORM SPLITS JUST OFFSHORE. THE REMNANT FRONT IN THE WAKE OF THE ERN US MIDLEVEL TROUGH WILL BEGIN TO MOVE SLOWLY NWD AS A WARM FRONT TODAY AND PROVIDE A FOCUS FOR ADDITIONAL STORM DEVELOPMENT THROUGH THE DAY. THOUGH MIDLEVEL TEMPERATURES AND LAPSE RATES ARE NOT PARTICULARLY FAVORABLE... RICH LOW-LEVEL MOISTURE AND EFFECTIVE BULK SHEAR OF 35-40 KT WILL SUPPORT A MARGINAL RISK FOR DAMAGING WINDS/HAIL.
..THOMPSON/MARSH.. 05/21/2016