256
FXUS63 KGID 061145
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
645 AM CDT WED AUG 6 2025
KEY MESSAGES
- BECOMING HOT AND HUMID THROUGH THE END OF THE WEEK. PEAK HEAT
INDICES OF 95-102F TODAY, THEN RISING TO 100-107F FOR THU-FRI.
- LOW END (20-30%) RAIN CHANCES THIS MORNING AND AGAIN LATE THIS
EVENING INTO THE OVERNIGHT. HOWEVER, BETTER CHANCES REMAIN TO
THE N AND E. DRY CONDITIONS EXPECTED THU THROUGH FRI AFTERNOON.
- COLD FRONT ARRIVES FRI EVENING/NIGHT AND LOWERS TEMPERATURES
AT LEAST A FEW DEGREES (ESP. IN CENTRAL NE) FOR THE WEEKEND,
THOUGH KS ZONES MAY STILL SEE HIGHS IN THE 90S. STRONGER PUSH
OF COOLER AIR ARRIVES EARLY NEXT WEEK.
- RAIN CHANCES RETURN ALONG AND BEHIND THE FRONT FRI EVE/NIGHT
AND CONTINUE OFF AND ON THROUGH THE WEEKEND, AND PERHAPS EVEN
INTO EARLY NEXT WEEK. DETAILS ARE UNCERTAIN, BUT NOT EXPECTING
DAYTIME "WASHOUTS" FOR LATE SUMMER WEEKEND PLANS.
DISCUSSION
ISSUED AT 445 AM CDT WED AUG 6 2025
ZONAL MID TO UPPER FLOW IS IN PLACE OVER THE CENTRAL PLAINS,
NORTH OF STRONG DOME OF HIGH PRESSURE CENTERED OVER NM. A
SHORTWAVE TROUGH IS NOTED OVER THE NORTHERN PLAINS INTO SOUTHERN
CANADA. AT THE SURFACE, SERLY FLOW REMAINS IN PLACE TO THE EAST
OF SEVERAL LEE SIDE LOW PRESSURE CENTERS OVER THE CENTRAL HIGH
PLAINS. A SFC BOUNDARY EXTENDS NE FROM ONE LOW PRESSURE NEAR CYS
TO THE NE INTO THE DAKOTAS, ALONG WHICH STORMS FORMED YESTERDAY
AFTERNOON/EVENING. THIS ACTIVITY GREW UPSCALE INTO A LARGE MCS
THAT IS NOW CENTERED OVER THE SIOUXLAND AREA. A FEW WEAK STORMS
HAVE TRIED TO FORM ALONG/E OF THE HWY 81 CORRIDOR OVER THE PAST
HOUR THAT IS TIED TO STRONG WAA ASSOCIATED W/ A VEERING LLJ.
FIRST FORECAST CHALLENGE OF THE DAY IS THE POTENTIAL FOR THE
AFOREMENTIONED MCS TO BACKBUILD INTO OUR FAR N/NE ZONES TOWARDS
DAWN TO MID MORNING AS THE LLJ CONTINUES TO VEER AND ASSOCIATED
OUTFLOW MAINTAINS A SOUTHWARD TRAJECTORY. UPWIND CORFIDI VECTORS
ALSO SUPPORT A CONTINUED SOUTHWARD DRIFT ALONG THE E PERIPHERY
OF THE UPPER HIGH AND MID LEVEL THERMAL RIDGE. EXTRAPOLATION OF
THE CURRENT HEADING/SPEED OF THE OUTFLOW BRINGS IT TO OUR N
BORDER AROUND 11Z, THOUGH COULD SEE SOME SLOWING - SO MAYBE
CLOSER TO 12Z. IN MY EXPERIENCE, THESE SYSTEMS OFTEN PERSIST
LONGER ON THE W FLANK, AND THUS OFTEN TO A LOWER LATITUDE, THAN
WHAT CAMS OFTEN PREDICT. OVERNIGHT HRRR RUNS HAVE ALREADY
STRUGGLED WITH CORRECT PLACEMENT OF THE SW EXTENT OF THE MCS, SO
THEY DON'T REALLY GIVE ME A LOT OF CONFIDENCE IN THEM MOVING
FORWARD. THEREFORE, HAVE LARGELY GONE WITH MORE OF THE
CONCEPTUAL MODEL AND KEPT SOME LOW END POPS OVER N-E ZONES
THROUGH ABOUT 13-14Z. WEAKENING LLJ SHOULD EVENTUALLY "TRANSFER"
ANY PROPAGATION FROM THE UPWIND VECTORS BACK TO MEAN WIND
VECTORS AND SHIFT THE WHOLE SYSTEM OFF TO THE E.
NEXT CHALLENGE THEN BECOMES ANTICIPATING PLACEMENT OF ANY
LINGERING OUTFLOW AND/OR DIFFERENTIAL HEATING BOUNDARIES AND
THEIR IMPACTS, IF ANY, ON AFTN/EVE CONVECTIVE POTENTIAL. WHILE
THE W FLANK OF THE OUTFLOW COULD MAKE IT INTO N ZONES THIS
MORNING, THE CURRENT ORIENTATION OF FEATURES SUGGESTS TO ME IT'S
UNLIKELY ANY OF THESE BOUNDARIES REMAIN IN OUR AREA INTO LATE
AFTN. RATHER, THESE BOUNDARIES SHOULD MAKE A NORTHWARD RETURN TO
AROUND THE NE/SD BORDER. WHAT HAPPENS AFTER THAT IN TERMS OF
CONVECTIVE INITIATION LOCATION, COVERAGE, TIMING REMAINS
UNCERTAIN AS CAM SOLUTIONS VARY. HRRR/RRFS SUGGEST SOME ISO-SCAT
DEVELOPMENT WILL BE POSSIBLE TOWARDS 23Z AROUND NORTH CENTRAL
NE, WHEREAS MOST OF THE OTHER HREF MEMBERS ARE MUCH QUIETER.
CAPPING WILL BE WEAKER IN THESE AREAS, BUT ANY MID-UPPER LEVEL
SUPPORT IS NEBULOUS, SO EITHER OUTCOME SEEMS PLAUSIBLE. IF
STORMS CAN FORM (HIGHLY CONDITIONAL) THEN THERE COULD BE A NON-
ZERO RISK FOR STRONG ACTIVITY TO MOVE INTO AREAS LIKE ORD TO
FULLERTON AFTER SUNSET AND BEFORE MIDNIGHT. AS SUCH, SPC EDGES
THE SOUTHERN EXTENT OF THE MARGINAL RISK INTO THESE AREAS
TONIGHT. 50-60 MPH WIND GUSTS PROBABLY THE MAIN THREAT.
UNCERTAIN IF ACTIVITY WOULD PERSIST INTO THE LATE OVERNIGHT AS
SOME LOOSELY ORGANIZED MCS, BUT BEST POTENTIAL FOR THIS, OR NEW
WAA DEVELOPMENT, WOULD BE FROM NORTHEAST INTO EASTERN NE ON THE
PERIPHERY OF THE UPPER RIDGE (I.E. "RING OF FIRE").
DESPITE THE DISCUSSION THUS FAR ABOUT RAIN CHANCES, THE MAIN
STORY AND WIDER REACHING IMPACT WILL BE THE INCREASINGLY HOT AND
HUMID CONDITIONS. EVEN TODAY, AREAS ALONG/S OF NE/KS BORDER
COULD SEE APPARENT TEMPS RISE INTO THE LOW 10S. HOWEVER, STILL
APPEARS THE BRUNT OF THIS ROUND OF HEAT/HUMIDITY WILL COME ON
THU AND FRI. NOT SURPRISINGLY, MODEL BLENDS HAVE TRENDED A BIT
HIGHER ON TDS (GLOBAL MODELS OFTEN UNDERESTIMATE THE EFFECTS THE
WIDESPREAD CROPS/IRRIGATION CAN HAVE ON INCREASING NEAR-SURFACE
MOISTURE), WHICH NOW EDGES A FEW AREAS INTO HEAT ADVISORY
CRITERIA (105-109F), MAINLY ON FRI. GIVEN THU'S VALUES ARE STILL
SOMEWHAT MARGINAL FOR CRITERIA AND WE'RE INTO THE "DOG DAYS OF
SUMMER", FELT BEST TO HOLD OFF ON ANY HEADLINE, FOR EITHER DAY.
OVERALL-HIGHEST AFTERNOON HUMIDITY WILL LIKELY FOCUS OVER
TYPICAL AREAS E OF HWY 281, AND ESP. ALONG HWY 81.
NEXT COLD FRONT LOOKS TO MOVE INTO THE REGION FRI EVENING.
UNCERTAIN IF STORMS WILL BE ABLE TO FORM ALONG THE ACTUAL FRONT
ITSELF IN OUR AREA DUE TO CAPPING FROM IMPRESSIVE MID LEVEL
THERMAL RIDGE (15-18C AT 700MB!). SEEMS UNLIKELY. MORE PLAUSIBLE
SCENARIO WOULD BE FOR ACTIVITY TO DEVELOP ALONG THE ELEVATED
FRONT IN NORTHERN NE WHERE CAPPING IS WEAKEN, THEN TRACK E/SE.
AGAIN, THOUGH, DETAILS STILL QUITE UNCERTAIN. FRONT THEN LOSES
SOME STEAM FRI NIGHT AND LOSES DEFINITION (ASSUMING NO OUTFLOW
REINFORCEMENT) ON SAT. TEMPS WILL COOL FROM FRI INTO THE
WEEKEND, BUT ESP. KS ZONES COULD STILL REMAIN HOT IN THE LOW-MID
90S. THE PRESENCE OF A DIFFUSE BAROCLINIC ZONE, AMIDST COOLER
MID LEVEL TEMPS AND ZONAL FLOW ALOFT, WILL KEEP OFF AND ON RAIN
CHANCES GOING THROUGH THE WEEKEND, AND EVEN INTO EARLY NEXT
WEEK. THOUGH, AS IS TYPICAL FOR THIS TIME OF YEAR, DON'T THINK
PEOPLE SHOULD GET TOO WORRIED YET ABOUT THE DAYTIME HOURS BEING
"WASHOUTS" FOR WEEKEND PLANS AS THERE SHOULD ALSO BE QUITE A BIT
OF DRY TIME BETWEEN ANY BOUTS OF SCATTERED RAIN. APPEARS A
SECONDARY PUSH OF COOL AIR ARRIVES IN TIME FOR EARLY NEXT WEEK
AND SHOULD RESULT IN 80S BEING MORE WIDESPREAD FOR A DAY OR TWO.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 642 AM CDT WED AUG 6 2025
FOR KGRI/KEAR AIRPORTS:
TODAY: STILL APPEARS ANY CONVECTION THIS MORNING WILL REMAIN NE
OF THE TERMINALS. HOWEVER, SOME LOW LEVEL WAVE CLOUDS ASSOCIATED
WITH OUTFLOW WILL LIKELY MOVE THROUGH IN THE 1230-1500Z TIME
FRAME, WITH BASES AROUND 1500FT. SHOULD REMAIN MOSTLY SCT/VFR,
BUT CAN'T COMPLETELY RULE OUT A FEW BRIEF PERIODS OF BKN/MVFR
CONDITIONS DURING THIS TIME. OTHERWISE, SHOULD BE MOSTLY SUNNY
THE REST OF THE DAY WITH PERHAPS SOME SCT AFTERNOON CU. WINDS
WILL BE SSE-S AROUND 8-13KT. CONFIDENCE: MEDIUM.
TONIGHT: VFR CONDITIONS EXPECTED WITH SE WINDS 6-10KT.
GID WATCHES/WARNINGS/ADVISORIES
NE...NONE.
KS...NONE.
DISCUSSION...THIES
AVIATION...THIES
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