978
FXUS63 KGID 181800
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
ISSUED BY NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1200 PM CST MON NOV 18 2024
KEY MESSAGES
- POTENT STORM SYSTEM WITH EXTREMELY ANOMALOUS DEEP LAYER
MOISTURE WILL BRING INCREASINGLY WIDESPREAD RAIN FROM SOUTH TO
NORTH THROUGHOUT THE DAY TODAY.
- HEAVIEST RAIN AMOUNTS (50-90% CHANCE FOR >1") WILL BE OVER
E/SE HALF OF THE FORECAST AREA, WITH RAPIDLY DECREASING
AMOUNTS FORECAST (0.50" OR LESS) W OF HWY 183. FAR W DAWSON
CO. MAY MISS OUT ON THIS EVENT ENTIRELY.
- MUCH COOLER AND BLUSTERY, BUT DRY CONDITIONS, EXPECTED TUESDAY
AND WEDNESDAY. AREAS ALONG/N OF I-80 WILL SEE NW WIND GUSTS
30-45 MPH, HIGHEST DURING THE DAYTIME WEDNESDAY.
- PERSISTENT NW UPPER FLOW WILL MAINTAIN NEAR-NORMAL
TEMPERATURES AND DRY CONDITIONS THROUGH THE REMAINDER OF THE
WEEK. SOME ENSEMBLE DATA SUGGESTS A MODEST WARM-UP WILL BE
POSSIBLE NEXT WEEKEND.
DISCUSSION
ISSUED AT 430 AM CST MON NOV 18 2024
NO SIGNIFICANT CHANGES TO RAIN TIMING OR AMOUNTS TODAY AS LATEST
OBSERVATIONAL DATA AND MODEL GUIDANCE SUGGESTS THE FORECAST
REMAINS ON TRACK. BY ALL INDICATIONS, THIS SYSTEM INDEED HAS
TREMENDOUSLY UNUSUAL DEEP LAYER MOISTURE TO WORK WITH, AND
WE'VE SEEN WIDESPREAD RAIN AND EMBEDDED CONVECTION RAPIDLY
BLOSSOM OVER THE S PLAINS EARLY THIS MORNING. THERE IS AN
OBVIOUS TROPICAL CONNECTION/PLUME NOTED ON WATER VAPOR IMAGERY,
AND SATELLITE IS ALSO SHOWING CLASSIC SIGNS OF AN UPPER LOW THAT
IS RAPIDLY DEEPENING/BEC NEGATIVELY TILTED AND HAS A TEXTBOOK
COUPLED UPPER JET STRUCTURE.
OVERALL TIMING SEEMS TO BE ON TRACK FOR RAIN TO STEADILY SPREAD
S/SE TO N/NW THROUGHOUT THE MORNING, WITH ALL BUT PERHAPS THE
ORD TO GOTHENBURG AREA HAVING AT LEAST SOME RAIN ACCUM BY NOON.
THE HEAVIEST RAIN THROUGH EARLY AFTN WILL BE OVER THE SE THIRD
OF THE CWA, CLOSER TO THE PRIMARY AND INTENSE LOW LEVEL MOISTURE
ADVECTION PLUME ON THE E/WARM SIDE OF THIS SYSTEM. EXPECT A
SECONDARY PLUME OF MODERATE RAIN TO DEVELOP EARLY TO MID AFTN
OVER W KS THAT RAPIDLY SHIFTS NE THROUGH MOST OF THE CWA DURING
THE LATE AFTN AND EVE HRS. THIS SECOND WAVE WILL BE DRIVEN MORE
BY MID TO UPPER LEVEL DYNAMICS (I.E. DEFORMATION AND
FRONTOGENESIS) AND PROVIDE THE CENTRAL THIRD (INCLUDING THE
TRI- CITIES) A BURST OF RAIN AMOUNTS SIMILAR TO OR EVEN HEAVIER
THAN EARLIER IN THE DAY. THIS ONE-TWO PUNCH SHOULD GIVE AREAS
ALONG/E OF A LINE FROM PHILLIPSBURG TO GREELEY A GOOD CHANCE
(50-95%) OF MEASURING AT LEAST 1" OF RAIN. AREAS EAST OF THIS
LINE CAN REASONABLY EXPECT 0.75-1.00" ON THE LOW END, TO
1.25-1.75" ON THE HIGH END (PARTICULARLY AREAS E OF HWY 281).
MODELS ARE NOW IN VERY GOOD AGREEMENT THAT A VERY SHARP GRADIENT
WILL SETUP FROM AROUND BEAVER CITY TO ORD WITH AMOUNTS POSSIBLY
VARYING BY OVER AN INCH OVER A SPAN OF JUST 30 MI, OR SO! FOR
EXAMPLE, THE 06Z HRRR GIVES SHELTON ~1.50", BUT MILLER ON THE
OTHER SIDE OF BUFFALO CO ONLY ~0.25"! AS A PROFESSIONAL WEATHER
PROGNOSTICATOR, I AM VERY HAPPY THIS ISN'T SNOW! MODELS ALSO
AGREE THAT AREAS LIKE GOTHENBURG AND COZAD COULD MISS OUT ON
THIS EVENT ENTIRELY OR ONLY SEE ~0.10". SEE CLIMATE SECTION
BELOW FOR DETAILS ON TODAY'S PRECIPITATION RECORDS.
THE OTHER SENSIBLE/IMPACTFUL WEATHER ITEM TO NOTE WILL BE INCR
WINDS THIS AFTN AS THE SFC LOW TRACKS NE FROM AROUND WICHITA TO
OMAHA. INTENSE LOW LEVEL PRESSURE GRADIENT, IN CONJUNCTION WITH
MODERATE RAIN RATES, COULD LEAD TO A 2-3 HR WINDOW OF GUSTS
40-45 MPH, AS INDICATED BY RECENT HI-RES GUIDANCE. IN FACT,
RECENT HRRR RUNS SUGGEST EVEN STRONGER GUSTS 45-55 MPH CAN'T BE
RULED OUT UNDER THE HEAVIEST RAIN BANDS. THE BOUNDARY LAYER WILL
BE EXTREMELY SHALLOW AND STABLE, SO HAVE NOT GONE THIS HIGH IN
RECENT GRIDS, BUT WILL PASS ALONG CONCERN TO DAY SHIFT.
RAIN VERY QUICKLY EXITS THE AREA FROM SW TO NE THIS EVENING.
THIS WAVE WILL COMBINED WITH ADDITIONAL TROUGHING COMING OUT OF
SW CANADA TO CARVE OUT A BIGGER LONG WAVE TROUGH OVER THE N
PLAINS ON TUE THAT PERSISTS INTO THE GREAT LAKES ON WED.
CONTINUED STRONG PRESSURE GRADIENT AND FAST NW MID-UPPER FLOW
WILL KEEP COOL AND BLUSTERY CONDITIONS GOING THROUGH BOTH
TUESDAY AND WEDNESDAY. PEAK GUSTS HAVE TRENDED LOWER ON RECENT
EPS GUIDANCE FOR WEDNESDAY, BUT STILL APPEARS AREAS ALONG AND
ESP N OF I-80 WILL HAVE POTENTIAL FOR 35-40 MPH GUSTS ON TUE,
AND 40-45 MPH GUSTS ON WEDNESDAY. WITH THE STEADY DOWNWARD TREND
IN THE 50 MEMBER EPS, THE NEED FOR WIND HEADLINES APPEARS
CONSIDERABLY LOWER NOW (<10%) THAN 24 HRS AGO (30-40%).
PERSISTENT NW UPPER FLOW WILL MAINTAIN NEAR TO SLIGHTLY BELOW
NORMAL TEMPERATURES THROUGH THE END OF THE WEEK, THOUGH WIND
GUSTS SHOULD DECR, ESP. FOR FRI. SOME ENSEMBLE GUIDANCE SHOWS A
MODEST WARM-UP ARRIVING FOR NEXT WEEKEND, WITH PERHAPS A RETURN
TO MORE WIDESPREAD HIGHS IN THE 50S. SO FAR, PRECIP CHCS APPEAR
VERY LOW TUE THROUGH EARLY NEXT WEEK.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1200 PM CST MON NOV 18 2024
FOR KGRI/KEAR AIRPORTS:
KEAR AND KGRI REMAIN ON THE NORTHWESTERN EDGE OF A POTENT LOW
PRESSURE SYSTEM BRINGING RAIN WITH LOW CLOUDS AND REDUCED VIS.
EXPECT PREDOMINANTLY IFR/LIFR CONDITIONS THROUGH THIS AFTERNOON
WITH IMPROVEMENT STARTING AROUND 23-02Z AS THE SYSTEM STARTS TO
MOVE OFF TO THE NORTHEAST. WINDS WILL SHIFT FROM NORTHERLY TO
MORE NORTHWESTERLY AS THIS SYSTEM EXITS, BUT REMAIN ELEVATED
WITH GUSTS TO 25 KT. WINDS ALOFT AROUND 2000 FT AGL WILL BE UP
AROUND 50-55 KT OVERNIGHT TONIGHT, LEADING TO AN EXTENDED PERIOD
OF LLWS. THESE WINDS ALOFT SHOULD EASE MID-MORNING TOMORROW,
WITH SOME UNCERTAINTY IN TIMING.
GID WATCHES/WARNINGS/ADVISORIES
NE...NONE.
KS...NONE.
DISCUSSION...STUMP
AVIATION...MCCOY (OAX)
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