May 7, 2014

Post date: May 7, 2014 1:36:51 PM

Wednesday, May 7, 2014 @ 0830 CDT: We ended up heading south yesterday, to Wichita Falls, TX, in the hopes that we would be in better position for favorable conditions today. Well, looking at the predictions by the SPC this morning, it looks like that is the case. We should finally have something to chase! Wooohoooo!!!

Here's a link to yesterday's shots, and yesterday's travel map as well:

Finally, here's the SPC discussion of what they are anticipating for today:

SPC AC 071256

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0756 AM CDT WED MAY 07 2014

VALID 071300Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL/SRN PLAINS...

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL HIGH PLAINS TO UPPER MS VALLEY REGION...

...SUMMARY...

SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON INTO THE OVERNIGHT HOURS FROM PARTS OF SOUTHERN KANSAS THROUGH WEST-CENTRAL TEXAS... THIS AFTERNOON AND EVENING OVER SOME OF THE CENTRAL HIGH PLAINS... AND TONIGHT OVER PARTS OF MINNESOTA AND WISCONSIN.

...SYNOPSIS...

IN MID-UPPER LEVELS... SYNOPTIC-SCALE TROUGHING CONTINUES TO PROGRESS SLOWLY ACROSS WRN NORTH AMERICA... MAIN COMPONENTS BEING MANIFEST AS 500-MB CYCLONES OVER NRN PORTIONS AB/SK AND OVER UT. STG SHORTWAVE TROUGH IS EVIDENT IN MOISTURE-CHANNEL IMAGERY EXTENDING SSWWD FROM UT LOW ACROSS WRN AZ TO NRN BAJA. AS OTHER... CURRENTLY LOWER-AMPLITUDE VORTICITY LOBES OVER ORE/CA DIG INTO SYNOPTIC-TROUGH POSITION... UT LOW WILL OPEN UP... AND AZ PORTION OF LEADING SHORTWAVE TROUGH WILL EJECT NEWD TO NRN NM AND SRN CO BY 00Z. THIS PERTURBATION SHOULD PROCEED NEWD ACROSS FRONT RANGE REGION OVERNIGHT... REACHING CENTRAL HIGH PLAINS BY 12Z WHILE TRAILING SYNOPTIC TROUGH CROSSES WRN BORDERS OF CO/NM. DOWNSTREAM... SUBSTANTIAL HEIGHT RISES ARE FCST OVER MUCH OF OH VALLEY AND GREAT LAKES... AS SYNOPTIC RIDGE SIMULTANEOUSLY AMPLIFIES AND MOVES EWD TO THOSE REGIONS.

AT SFC... 11Z ANALYSIS SHOWED ELONGATED AREA OF LOW PRESSURE ALONG QUASISTATIONARY FRONTAL ZONE FROM SERN NEB SWWD ACROSS NWRN KS TO E-CENTRAL CO. ONLY MINOR/LOCALIZED SHIFTS ARE EXPECTED WITH THAT PORTION OF FRONT THROUGH 00Z. MEANWHILE LOW-PRESSURE AREA WILL ELONGATE FURTHER AND BECOME BIMODAL -- ONE LOW OVER ERN CO... ANOTHER SHIFTING NEWD OVER ERN NEB INTO NERN IA. ACCORDINGLY... WARM FRONT INITIALLY FROM SERN NEB ACROSS EXTREME SRN IA AND N-CENTRAL IL WILL MOVE NWD TO EXTREME SRN MN AND SRN WI BY 00Z. BY END OF PERIOD... PRIMARY SFC CYCLONE MAY TAKE SHAPE OVER SWRN/CENTRAL NEB. BY 12Z... WARM FRONT ALSO SHOULD MOVE NWD ACROSS OH VALLEY AND PARTS OF CENTRAL APPALACHIANS TO REACH WRN PA AND SRN LOWER MI.

DRYLINE HAS BECOME WELL-ESTABLISHED FROM NRN COAHUILA NNEWD ACROSS NW TX... W-CENTRAL KS... TO FRONTAL INTERSECTION OVER EXTREME S-CENTRAL NEB. ONLY MESOBETA SCALE SHIFTS TO THAT POSITION ARE EXPECTED THROUGHOUT DAYLIGHT HOURS... MAINLY AS SLGT EWD MIXING FROM NW TX ACROSS WRN OK TO SRN KS... FOLLOWED BY PRONOUNCED WWD RETREAT AFTER 00Z.

...SRN/CENTRAL PLAINS INVOF DRYLINE... AFTN/EVENING...

MOIST ADVECTION E OF DRYLINE WILL INCREASE PW ACROSS N-S CORRIDOR OF CENTRAL TX/OK AND CENTRAL-ERN KS TODAY... WHILE STG INSOLATION DESTABILIZES LOW-LEVEL LAPSE RATES AND REMOVES CINH. SFC DEW POINTS SHOULD MIX DOWNWARD JUST E OF DRYLINE... RESULTING IN INITIALLY HIGH-BASED CONVECTION ATOP DEEP SUBCLOUD LAYER. BY MID-LATE AFTN... EXPECT WIDELY SCATTERED TO SCATTERED TSTMS IN 50-100-NM-WIDE CORRIDOR ALONG/AHEAD OF DRYLINE. TSTMS ALSO SHOULD INITIATE ON HIGHER TERRAIN OF NRN COAHUILA WITH POTENTIAL TO CROSS RIO GRANDE INTO TX.

WITHIN FIRST FEW HOURS OF CONVECTIVE CYCLE... SMALL HODOGRAPH CURVATURE AND NEAR-SYMMETRY OF PROJECTED LEFT- AND RIGHT-MOVING CELL MOTIONS ABOUT HODOGRAPHS SUGGEST PROPENSITY FOR STORM SPLITS AND PERHAPS EVEN IN-SITU LEFT-MOVER FORMATION. ACCORDINGLY... SOME CONVECTION-ALLOWING GUIDANCE PREDICTS GREATER LONGEVITY FOR LEFT-MOVERS THAN RIGHT-MOVERS DURING THIS DIURNAL TSTM STAGE. WHETHER OR NOT THAT VERIFIES... SEVERAL SUPERCELLS WITH LARGE AND POTENTIALLY DAMAGING HAIL APPEAR PROBABLE... ALONG WITH OCNL STG-SVR GUSTS.

AS DRYLINE RETREATS... INCREASING MOISTURE TO ITS E MAY ADVECT INTO INFLOW REGION OF PRE-EXISTING CONVECTION THAT ORIGINATED BEFORE 00Z... AND/OR ANY ADDITIONAL DEVELOPMENT EARLY THIS EVENING. 2-3 HOUR TIME WINDOW MAY EXIST TO JUXTAPOSE THAT PROCESS... OFFERING POTENTIAL TO MAINTAIN RELIABLY SFC-BASED EFFECTIVE-INFLOW PARCELS... WITH POSITIVE-SRH/HODOGRAPH ENLARGEMENT RELATED TO STRENGTHENING LLJ. IN THAT EVENT... ANY PERSISTENT/WELL-ORGANIZED SUPERCELLS COULD POSE SLGT TORNADO RISK. OTHERWISE... LARGE-HAIL AND SEVERE-GUST THREATS SHOULD BE MAINTAINED. ANOTHER ROUND OR TWO OF EVENING/OVERNIGHT TSTM DEVELOPMENT APPEARS PROBABLE INVOF DRYLINE OVER WRN OK AND/OR W TX... LEADING TO NEWD-MOVING MIX OF STORM MODES AND ADDITIONAL SVR POTENTIAL. OUTLOOK AREA REPRESENTS WHOLE-PERIOD AGGREGATE OF ALL THESE EPISODES.

...CENTRAL HIGH PLAINS TO SRN SD...

COOL MORNING BOUNDARY LAYER BEHIND SFC FRONT GRADUALLY WILL DESTABILIZE THROUGHOUT DAYLIGHT HOURS AMIDST SUSTAINED SFC HEATING... WHILE VEERING OF INITIALLY NLY FLOW BEGINS TO ADVECT HIGHER-THETAE AIR UPSLOPE. BY MID-LATE AFTN... THESE PROCESSES SHOULD REMOVE ENOUGH CINH TO SUPPORT WIDELY SCATTERED TO SCATTERED TSTM DEVELOPMENT OVER NERN CO... SERN WY AND SRN NEB PANHANDLE. STEEP LOW-MIDDLE-LEVEL LAPSE RATES AND SFC DEW POINTS MID-40S TO NEAR 50 F IN MODIFIED FCST SOUNDINGS SUPPORT 1000-2000 J/KG MLCAPE... WHILE ELONGATED LOW-LEVEL HODOGRAPHS AND 45-55 KT EFFECTIVE-SHEAR MAGNITUDES SUGGEST SUPERCELLS AND BOWS ARE POSSIBLE. LARGE HAIL... SOME SIGNIFICANT... WITH DAMAGING GUSTS AND A TORNADO OR TWO ARE POSSIBLE.

ACTIVITY MAY AGGREGATE INTO ONE OR TWO LARGER CLUSTERS THIS EVENING WHILE MAINTAINING WIND/HAIL RISK FOR SEVERAL HOURS. SOME OF THIS CONVECTION MAY REACH PORTIONS SRN SD WITH POTENTIAL FOR SVR HAIL AND SPORADIC STG-SVR GUSTS TONIGHT... WHILE ADDITIONAL HAIL-PRODUCING TSTMS POSSIBLY FORM INVOF FOOTHILLS OF NRN CO AND SERN WY.

...MN/WI REGION OVERNIGHT...

GIVEN ANTECEDENT ADVECTION OF EML OVER THIS REGION... SFC FRONTAL ZONE SHOULD REMAIN CAPPED FOR TSTMS THROUGH DAYLIGHT HOURS. AFTER DARK... NOSE OF 45-60 KT LLJ WILL IMPINGE ON ELEVATED WARM-FRONTAL SFC AS PART OF STG/ELEVATED/LOW-LEVEL WAA REGIME. THIS WILL RAISE INCREASINGLY MOIST PARCELS TO LFC AND HELP TO MAINTAIN STEEP LAPSE RATES ATOP FRONTAL SFC... CONTRIBUTING TO MUCAPE IN 2000-3000 J/KG RANGE. EVEN WITHOUT APPRECIABLE UPPER-AIR PERTURBATIONS... SUCH LARGE BUOYANCY WITHIN 35-45 KT EFFECTIVE-SHEAR MAGNITUDES WILL SUPPORT LARGE HAIL... AND ISOLATED STG/DAMAGING GUSTS CANNOT BE RULED OUT.

..EDWARDS/LEITMAN.. 05/07/2014

Wednesday, May 7, 2014 @ 1145 CDT: We have left Wichita Falls and are moving slightly NNW now, towards Vernon, TX. Then it will probably be a "Hurry up and wait" kind of day. We're expecting things to start popping up some time after 4 pm CDT.