945
FXUS63 KOAX 291722
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1222 PM CDT TUE JUL 29 2025
KEY MESSAGES
- DANGEROUS HEAT WILL REMAIN IN PLACE FOR PARTS OF THE AREA
TUESDAY. EXPECT AFTERNOON HEAT INDEX VALUES OF 100 TO 110
DEGREES, HIGHEST SOUTH OF HIGHWAY 30.
- WIDESPREAD STORMS ARE EXPECTED TUESDAY AFTERNOON INTO THE
EVENING (60-90% CHANCE). THERE IS A 15-30% CHANCE OF SEVERE
STORMS, WITH DAMAGING WINDS AND LOCALIZED FLOODING THE PRIMARY
THREATS.
- COOLER CONDITIONS RETURN WEDNESDAY INTO THE WEEKEND.
DISCUSSION
ISSUED AT 350 AM CDT TUE JUL 29 2025
WATER VAPOR IMAGERY IS DOMINATED BY THE ANTI-CYCLONIC FLOW OF A
598DAM RIDGE CENTERED OVER ARKLATEX AND A WISCONSIN-SIZED AREA
OF COLD CLOUD-TOPS ASSOCIATED WITH A RIDGE-RIDING DERECHO
FLATTENING A WIDE SWATH OF IOWA CORN. THIS CWA WAS JUST SKIRTED
BY THIS POWERFUL SYSTEM AND - FOR THE SECOND NIGHT IN A ROW -
ENJOYED AN OVERNIGHT REPRIEVE FROM THE HEAT THANKS TO THE
PASSING SYSTEM'S COLD POOL. BOTH NIGHTS BROUGHT A QUICK DROP OF
TEN PLUS DEGREES FAHRENHEIT TO BOTH AIR TEMP AND DEWPOINT.
THIS RERUN OF YESTERDAY'S EPISODE GIVES CONFIDENCE TO TODAY'S
ABILITY TO EASILY MIX OUT THE SHALLOW COOLER/DRIER AIR AND
ALLOW THE SOUTHERN HALF OF THE CWA TO PUSH INTO HEAT ADVISORY
CRITERIA ONE MORE TIME THIS AFTERNOON. MODEL GUIDANCE HAS BEEN
PRETTY CONSISTENT IN DRAPING THAT FRONT FROM ABOUT ONAWA, IA
THROUGH ABOUT COLUMBUS, NE. THIS MATCHES WELL WITH OUR STANDING
HEAT ADVISORY FOR TUESDAY AFTERNOON, SO NO CHANGES WERE MADE
THERE. WE CONTINUE TO EXPECT HEAT INDICES TO PEAK BETWEEN 102
TO 109 IN THIS AREA. AREAS NORTH OF THE BOUNDARY WILL LEVEL OFF
IN THE 80S WITH HEAT INDICES FALLING SHY OF THE CENTURY MARK.
SOME UNCERTAINTY DOES REMAIN WITH THE CONVECTIVE OUTFLOW PERHAPS
PUSHING THAT COLD FRONT A BIT OFF COURSE. WILL BE WATCHING
SURFACE OBS CLOSELY THIS MORNING IN AN ATTEMPT TO PICK OUT ANY
REMAINING BOUNDARIES THAT MAY THROW WRENCHES INTO THE FORECAST.
IF ALL FALLS OUT AS ANTICIPATED AND LEFTOVER OUTFLOW BOUNDARIES
DON'T INTERFERE WITH EXPECTED CONVECTIVE INITIATION, THE
FRONT'S LOCATION ACROSS THE AREA WILL ALSO HIGHLIGHT THE AREA
WITH BEST CONVERGENCE. GUIDANCE SEEMS TO PREFER TO INITIATE THE
CONVECTION OVER THE HIGHER TERRAIN OF THE ROCKIES AND PUSH IT
EAST THROUGH CENTRAL NEBRASKA IN THE AFTERNOON HOURS. WITH THE
STRONGEST H7 AND H5 WINDS ACROSS THE DAKOTAS/MN, SHEAR WILL BE
QUITE WEAK. POPCORN VARIETY STORMS MAY DEVELOP OVER THE HIGH
PLAINS OF EASTERN COLORADO/WESTERN NEBRASKA BEFORE AMALGAMATING
INTO A LINE OR MCS AND PUSH FROM NORTHWEST TO SOUTHEAST ACROSS
THIS AREA ON TUESDAY EVENING (6PM TO 3AM?). WIND WILL BE A
MAJOR THREAT ONCE AGAIN.
LET'S NOT FORGET THAT FLASH FLOODING IS ALSO SEVERE WEATHER.
PRECIPITABLE WATER WILL BE NEAR 2" AND ABOVE NORMAL FOR LATE
JULY (NAEFS). WARM CLOUD DEPTHS WILL BE ABOUT 4,000M. AND WITH
A CORFIDI VECTOR OF ONLY ABOUT 10 KNOTS, BACKBUILDING STORMS
WILL BE A THREAT. THE HREF PUTS ABOUT A 30% CHANCE OF 2" OF
PRECIP IN THE OMAHA METRO AREA BETWEEN 1AM AND 7AM. IT ALSO
SUGGESTS THAT A LARGE SWATH OF THE AREA COULD SEE 1-2" (PMM).
QPF REFLECTS JUST THAT WITH THE BULLSEYE IN WESTERN IOWA.
WEDNESDAY
SHOWERS AND STORMS WILL TAPER AND END OVER THE COURSE OF THE
DAY ON WEDNESDAY WITH THE CLOUD-COVER STUBBORNLY HANGING TIGHT.
HIGHS WILL SPIN THEIR WHEELS IN THE 70S AND 80S.
END OF THE WEEK
AS THE COOL SURFACE HIGH PRESSURE SETTLES INTO THE HIGH PLAINS /
GREAT LAKES ON THURSDAY, THE COLD FRONT WILL JOG SOUTH. THIS
WILL HELP KEEP TEMPS COOL THROUGH SATURDAY BEFORE A PROSPECTIVE
SHORTWAVE PUSHES THROUGH ON SATURDAY NIGHT OR SUNDAY, BRINGING A
30% CHANCE OF SHOWERS AND STORMS.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1218 PM CDT TUE JUL 29 2025
VFR CONDITIONS ARE EXPECTED AT LEAST THROUGH THE FIRST 6 HOURS
OF THE TAF PERIOD. TS POTENTIAL BEGINS AT ALL SITES AT
APPROXIMATELY 00UTC, BUT SHOULD INITIALLY BE WIDELY SCATTERED.
AS WE GO TOWARD 03 AND 05 UTC, TS COVERAGE SHOULD INCREASE WITH
GREATER POTENTIAL TO IMPACT TAF SITES. THEN A LARGE CLUSTER OF
STORMS WILL TRACK FROM WEST TO EAST, AND HAVE FOCUSED A TWO HOUR
WINDOW ON THE MOST LIKELY TIME FRAME FOR THESE STORMS TO IMPACT
TAF SITES BEFORE TRANSITIONING BACK TO SHRA (WITH SOME
OCCASIONAL TS POTENTIAL). ALSO EXPECT LOWER CEILINGS TO BUILD IN
TO ALL SITES CLOSER TO 12 UTC AND THROUGH THE END OF THE TAF.
OAX WATCHES/WARNINGS/ADVISORIES
NE...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR NEZ042>045-050-
065-078-088>093.
EXTREME HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR
NEZ051>053-066>068.
IA...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR IAZ055-056.
EXTREME HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR IAZ069-
079-080-090-091.
DISCUSSION...BARJENBRUCH
AVIATION...NICOLAISEN
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