685
FXUS63 KSGF 201030
AFDSGF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
530 AM CDT TUE MAY 20 2025
KEY MESSAGES
- MARGINAL (1 OF 5) TO SLIGHT (2 OF 5) RISK FOR SEVERE
THUNDERSTORMS EAST OF HIGHWAY 65 BEFORE 5 PM TODAY. HAIL UP TO
HALF DOLLARS AND WIND GUST UP TO 60 MPH WILL BE THE MAIN
HAZARDS, BUT A BRIEF WINDOW FOR A TORNADO CANNOT BE RULED OUT.
- COOLER AND RELATIVELY DRIER FOR THE REST OF THIS WEEK, THOUGH
A FEW ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE WEDNESDAY
NIGHT (15-20% CHANCE).
- THE PATTERN IS STARTING TO LOOK A BIT SOGGY FOR MEMORIAL DAY
WEEKEND WITH DAILY 40-70% RAIN CHANCES AND INCREASING MODEL
AGREEMENT FOR WIDESPREAD RAINFALL ACCUMULATION.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 330 AM CDT TUE MAY 20 2025
CURRENT WATER VAPOR IMAGERY SHOWS A DEEP NEGATIVELY-TILTED MID-
AND UPPER-LEVEL TROUGH DIGGING ACROSS THE PLAINS STATES WITH A
100+ KT UPPER-LEVEL JET STREAK REACHING OVER THE OZARKS. BENEATH
THE STRONG JET STREAK DYNAMIC LIFT, AN ELONGATED SURFACE LOW IS
ANALYZED OVER EAST KS/NE/OK WITH A SURFACE COLD FRONT STRETCHING
SOUTH INTO TX. THE SURFACE LOW LOOKS TO BE REINFORCED ON THE
BACKSIDE WITH AN MCV/WAKE-LOW TYPE SYSTEM FROM A THUNDERSTORM
COMPLEX ACROSS EAST-CENTRAL KS. ALONG THE LEADING EDGE OF THIS
SYSTEM, NON-THUNDERSTORM WIND GUSTS GREATER THAN 60 MPH HAVE
BEEN OBSERVED BY ASOS STATIONS. A HIGH WIND WARNING IS IN PLACE
ACROSS EAST-CENTRAL KS. THIS SYSTEM WILL CONTINUE TO BE
MONITORED FOR POTENTIALLY ENTERING OUR AREA FROM THE WEST, WHICH
COULD BRING SOME ENHANCED NORTHWESTERLY WIND GUSTS EARLY THIS
MORNING.
THE FLOOD WATCH IS SET TO EXPIRE BY 7 AM THIS MORNING.
LINGERING RISK FOR SEVERE THUNDERSTORMS TODAY:
THE THUNDERSTORM COMPLEX THAT BROUGHT YESTERDAY'S SEVERE THREAT
HAS EXITED THE AREA FOR THE NIGHT. CURRENT RADAR TRENDS SHOW
ADDITIONAL STORMS DEVELOPING IN NE OK AND NW AR WITH RAP
MESOANALYSIS SHOWING 500-1000 J/KG OF UNCAPPED ELEVATED
INSTABILITY RE-ENTERING THE REGION FROM THE SOUTH. THUS, SOME
DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS ARE STILL
POSSIBLE, ESPECIALLY ACROSS SOUTHERN MISSOURI THROUGH THE REST
OF TONIGHT (30-50% CHANCE).
THIS UNCAPPED ELEVATED UNSTABLE AIR MASS WILL HANG AROUND ACROSS
OUR AREA THIS MORNING. AFTER 5-7 AM OR SO, THE SURFACE COLD
FRONT WILL ENTER OUR REGION FROM THE WEST. WITH RAP FORECASTING
SOME UNCAPPED ELEVATED PARCELS AVAILABLE, SOME SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ALONG THE FRONT WITH THE POTENTIAL
FOR SMALL HAIL AND PERHAPS WIND GUSTS UP TO 40-50 MPH IN ANY
STRONGER CELL THAT CAN DEVELOP.
THE BETTER CHANCE FOR SHOWER AND THUNDERSTORM REDEVELOPMENT WILL
BE DURING THE LATE MORNING INTO THE MID-AFTERNOON HOURS EAST OF
HIGHWAY 65 WHERE MOISTURE ADVECTION AHEAD OF THE FRONT SHOULD
BEGIN DISSOLVING THE STABLE AIR LEFT BEHIND BY LAST NIGHT'S
SYSTEM. WHETHER WE SEE STORMS WILL DEPEND ON THE SPEED OF
DESTABILIZATION BEFORE THE FRONT COMPLETELY EXITS OUR AREA BY 5
PM. GIVEN FORECASTED UNCAPPED ELEVATED INSTABILITY, HOWEVER, AT
LEAST A FEW SCATTERED ELEVATED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE (30-50% CHANCE).
WITH ANY DEVELOPMENT ALONG THE FRONT, THERE IS A MARGINAL (1 OF
5) RISK FOR SEVERE THUNDERSTORMS EAST OF HIGHWAY 65, AND A
SLIGHT (2 OF 5) RISK EAST OF HIGHWAY 63. AFTER 9-11 AM, HREF
AND RAP SOUNDINGS HAVE 1000-1500 J/KG MLCAPE AND UPWARDS OF
1500-2500 J/KG MUCAPE BENEATH 50-60 KTS 0-6 KM BULK SHEAR THANKS
TO THE STRONG JET STREAK MOVING OVERTOP. THEREFORE, ANY STORMS
THAT DO DEVELOP WILL HAVE THE POTENTIAL TO BECOME STRONG TO
SEVERE. THE MAIN HAZARDS LOOK TO BE HAIL UP TO HALF DOLLARS
GIVEN MODEST CAPE AND 7-7.5 C/KM MID-LEVEL LAPSE RATES, THEN WIND
GUSTS UP TO 60 MPH. THERE COULD BE A BRIEF WINDOW FOR AN
ISOLATED TORNADO ACROSS THE EASTERN OZARKS. AS DAYTIME MIXING
COMMENCES, RAP AND HREF BEGIN ERODING THE CAPPING INVERSION.
SIMULTANEOUSLY, DUE TO THE MIXING, THE LOW-LEVEL JET BEGINS
WEAKENING. THEREFORE, SURFACE-BASED INSTABILITY INCREASES AHEAD
OF THE FRONT, WHILE 0-1 KM SHEAR AND SRH DECREASES. IF ANY STORM
CAN DEVELOP IN THE SWEET SPOT WHERE LOW-LEVEL SHEAR IS STILL
SUFFICIENT, A TORNADO CANNOT BE RULED OUT. THE BEST TIMING FOR
POTENTIAL SEVERE STORMS WILL BE BETWEEN NOON AND 5 PM. THE RISK
SHOULD BE OUT OF OUR AREA AS THE FRONT IS PROGGED TO CLEAR EAST
AFTER 5 PM.
THE COLD FRONT PASSAGE WILL BRING IN COOLER AIR WITH HIGHS
RANGING FROM NEAR 70 ALONG THE MO/KS BORDER, TO NEAR 80 IN
SOUTH-CENTRAL MO. THEN, LOWS IN THE UPPER 40S AND LOWER 50S
APPEAR LIKELY TONIGHT.
LONG TERM /WEDNESDAY THROUGH MONDAY/
ISSUED AT 330 AM CDT TUE MAY 20 2025
COOLER AND RELATIVELY DRIER FOR THE REST OF THIS WEEK:
THE UPPER-LEVEL JET CORE IS FORECAST TO SETTLE OVER OUR REGION
WEDNESDAY, WITH THE SURFACE COLD FRONT STALLING JUST TO OUR
SOUTH. THIS WILL ALLOW COOLER AIR TO FILTER IN FOR THE REST OF
THE WEEK. NBM DETERMINISTIC HAS HIGHS HOVERING IN THE UPPER 60S
AND LOWER 70S WEDNESDAY THROUGH THE WEEKEND, WITH LOWS IN THE
LOWER TO MIDDLE 50S. NBM SPREADS ARE PRETTY CONFIDENT IN AT
LEAST ONE OR TWO NIGHTS WHERE LOW TEMPERATURES DROP TO THE
MIDDLE TO UPPER 40S. THESE WOULD BE WEDNESDAY AND THURSDAY
NIGHT.
CONFIDENCE IN TEMPERATURES ARE LOWER INTO THE WEEKEND AS
MODELS DEPICT VARIATIONS IN THE POSITION OF THE COLD FRONT.
25TH-75TH NBM SPREADS RANGE FROM 65-75 F FOR SPRINGFIELD
SATURDAY AND MONDAY, WITH SPREADS FROM 65-80 F SUNDAY. THE NBM
DETERMINISTIC IS STICKING CLOSER TO THE LOWER END OF THE RANGE,
BUT IF THE COLD FRONT HANGS A BIT NORTH, WARMER TEMPERATURES ARE
POSSIBLE OVER THE WEEKEND.
15-20% CHANCE FOR ISOLATED THUNDERSTORMS WEDNESDAY NIGHT:
NORTHWESTERLY FLOW WILL TAKE HOLD OF THE AREA WEDNESDAY INTO
WEDNESDAY NIGHT. THE MAIN SURFACE COLD FRONT IS PROGGED TO BE
ACROSS THE GULF COAST DURING THIS TIME FRAME, BUT A SECONDARY
BOUNDARY LOOKS TO BE POSITIONED JUST SOUTH OF THE AREA. THE
MAIN FRONT SHOULD KEEP DEEP GULF MOISTURE DOWN SOUTH, BUT GLOBAL
MODELS AND SOME HI-RES GUIDANCE SUGGEST WEAK CLOCKWISE/SOUTHERLY
SURFACE FLOW IN AR/OK THAT MAY PULL UP SOME RESIDUAL MOISTURE
BEHIND THE MAIN FRONT. BEING QUITE FRANK, IT DOES LOOK LIKE
MOISTURE IS PULLED OUT OF THIN AIR FROM THE MODELS, SO NOT SURE
WHETHER TO BELIEVE IT OR NOT AS THERE ISN'T REALLY A GOOD
PHYSICAL REASON BEHIND IT OTHER THAN WEAK MOISTURE ADVECTION
BEHIND THE MAIN FRONT.
ANYWAYS, IF THIS SCENARIO INDEED DOES OCCUR, ELEVATED
INSTABILITY OF AT LEAST 500 J/KG COULD DEVELOP OVER OUR AREA
(THE COOL SIDE OF THE BOUNDARY). GLOBAL MODELS LIKE THE GFS AND
ECMWF SUGGEST UPWARDS OF 1000-1500 J/KG MUCAPE. WITH THE JET
CORE POSITIONED OVER THE BOUNDARY, DEEP-LAYER SHEAR WILL BE UP
TO 50-70 KTS. THUS, ISOLATED TO SCATTERED THUNDERSTORM
DEVELOPMENT IS POSSIBLE AS THE LOW-LEVEL JET SLIGHTLY
STRENGTHENS TO 20-25 KTS OVER THE BOUNDARY WEDNESDAY NIGHT
(15-20% CHANCE). MOST CAMS ARE A BIT LACKLUSTER IN MOISTURE, BUT
SOME--LIKE THE NSSL WRF AND A FEW MEMBERS OF THE EXPERIMENTAL
MPAS ENSEMBLE--DO PROVIDE SUFFICIENT MOISTURE FOR A FEW ELEVATED
SUPERCELLS THAT WOULD BRING A LARGE HAIL THREAT. CURRENTLY, THE
SPC HAS US IN A GENERAL THUNDER, BUT THEY DO MENTION THIS
POTENTIAL SCENARIO THAT COULD INTRODUCE A MARGINAL (1 OF 5) RISK
IN FUTURE OUTLOOKS FOR WEDNESDAY NIGHT.
INCREASING CONFIDENCE IN SOGGY PATTERN FOR MEMORIAL DAY WEEKEND:
THAT SECONDARY BOUNDARY IS PROGGED TO HANG AROUND THE REGION,
SLIGHTLY GAINING A MORE NW TO SE ORIENTATION AS A VERY SLOW-
MOVING WARM FRONT AS SYNOPTIC-SCALE RIDGING LOLLYGAGS INTO THE
CENTRAL PLAINS. MODEST WESTERLY FLOW ALOFT OVER THE ROCKIES
SHOULD PRODUCE LEE-CYCLOGENESIS ALLOWING FOR AMPLIFICATION OF
THE NIGHTLY LOW-LEVEL JET ACROSS THE SOUTHERN PLAINS. THE NOSE
OF THIS JET WOULD THEN MOVE OVERTOP THE SURFACE BOUNDARY-WARM
FRONT. THIS PATTERN IS EXPECTED TO STICK AROUND, OR MORE APTLY
PUT, SLOWLY EVOLVE THROUGH MEMORIAL DAY WEEKEND. THE LOW-LEVEL
JET OVERTOP THE WARM FRONT ALONG WITH SUBTLE SHORTWAVE ENERGY
PULSES ROUNDING THE RIDGE LOOKS TO PRODUCE DAILY CHANCES FOR
SHOWERS AND THUNDERSTORMS FOR POTENTIALLY EXTENDED PERIODS
(DAILY 30-50% CHANCES). THE GREATER COVERAGE OF THESE STORMS
WOULD BE AT NIGHT WHEN THE NOCTURNAL LOW-LEVEL JET AND
ASSOCIATED MOISTURE TRANSPORT IS STRONGEST (NIGHTLY 50-70%
CHANCES). THIS PATTERN COULD MAKE FOR A WET AND SOGGY MEMORIAL
DAY WEEKEND.
TO CORROBORATE AND INCREASE CONFIDENCE ON WHAT IS BEING SEEN IN
THE SYNOPTIC PATTERN, THE EXTREME FORECAST INDEX IS STARTING TO
HIGHLIGHT 0.5-0.7 VALUES FOR QPF ACROSS THE OZARKS WITH A SHIFT
OF THE TAIL ALREADY PRESENT, SIGNIFYING THAT SOME MEMBERS ARE
DEPICTING HIGHER RAINFALL AMOUNT SOLUTIONS. ENSEMBLE QPF
CLUSTERS DEPICT 25-50% OF MODELS WITH GOOD AGREEMENT IN AREAS
SEEING AT LEAST 0.5-2 INCHES EACH DAY OVER THE WEEKEND WITH
NEARLY ALL MODELS SHOWING SOME LEVEL OF RAINFALL AMOUNTS. THE
NBM 25TH-75TH PERCENTILE SPREAD FOR THE WEEKEND'S TOTAL
PRECIPITATION THROUGH MONDAY MORNING IS CURRENTLY AT 2-4 INCHES,
WHICH IS IN LINE WITH OUR CURRENT DETERMINISTIC QPF FORECAST.
SOME PROBABILISTIC DATA FOR TOTAL RAINFALL THROUGH MEMORIAL
WEEKEND IS BELOW:
PERCENT CHANCE FOR >0.50": 75-90%
PERCENT CHANCE FOR >1.00": 60-75%
PERCENT CHANCE FOR >2.00": 35-55%
PERCENT CHANCE FOR >4.00": 10-20%
AT THE MOMENT, THERE IS NO FAVORED LOCATION FOR HIGHER AMOUNTS
AS THE CLUSTER SWATHS IS PRETTY MUCH OVER THE ENTIRETY OF OUR
CWA. THE WPC IS IN AGREEMENT WITH THE POTENTIAL FOR A WET
WEEKEND AS THEY HAVE US IN A MARGINAL (1 OF 4) RISK FOR
EXCESSIVE RAINFALL FRIDAY, AND A SLIGHT (2 OF 5) RISK FOR OUR
ENTIRE CWA SATURDAY. ADDITIONALLY, THEY HAVE THE ENTIRE STATE OF
MISSOURI HIGHLIGHTED FOR A RISK FOR HEAVY RAIN BETWEEN FRIDAY
AND SUNDAY.
DETAILS WILL CONTINUE TO BE IRONED OUT AS WE GET CLOSER TO THE
WEEKEND, BUT BOTTOM LINE FOR NOW IS TO BE PREPARED FOR MULTIPLE
ROUNDS OF MORE WIDESPREAD/PROLONGED RAINFALL DURING MEMORIAL DAY
WEEKEND. KEEP UP WITH THE FORECAST, ESPECIALLY IF YOU ARE
PLANNING TO BE DOING OUTDOOR ACTIVITIES, ESPECIALLY CAMPING NEAR
RIVERS AND CREEKS.
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
ISSUED AT 530 AM CDT TUE MAY 20 2025
AS OF 1030Z, A COLD FRONT IS JUST TRAVERSING JLN AND WILL
CONTINUE WEST TO EAST THROUGH THE EARLY PART OF THE PERIOD.
THERE IS A 20-40% CHANCE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS DEVELOP AHEAD OF THE FRONT DURING THE 12-17Z
TIMEFRAME. AS THE FRONT PASSES, SOUTHEASTERLY WINDS WILL SHIFT
TO WESTERLY WITH SUSTAINED WINDS AT 13-18 KTS AND GUSTS UP TO
23-28 KTS AT TIMES.
PRECEDING THE FROPA, CIGS SHOULD DECREASE TO THE MVFR RANGE
(50-70% CHANCE). GIVEN THE EXITING MCS AND SCATTERED SHOWER
ACTIVITY, CLOUD DEBRIS WILL BE PREVALENT AT DIFFERENT LEVELS.
CIGS SHOULD THEN CLEAR OUT TO A 4KFT CU FIELD BEHIND THE FROPA
BY 17Z.
SGF WATCHES/WARNINGS/ADVISORIES
KS...NONE.
MO...NONE.
SHORT TERM...PRICE
LONG TERM...PRICE
AVIATION...PRICE
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