617
FXUS63 KSGF 172307
AFDSGF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
607 PM CDT THU SEP 17 2026
KEY MESSAGES
- A HEAT ADVISORY IS IN EFFECT THROUGH SATURDAY. HIGHS NEAR 100
WITH HEAT INDEX VALUES 100-105 CAN BE EXPECTED. SEVERAL DAILY
RECORDS MAY BE TIED OR BROKEN.
- ISOLATED SHOWERS AND STORMS THIS AFTERNOON, PARTICULARLY
ACROSS THE EASTERN OZARKS AND SOUTH-CENTRAL MISSOURI.
- COOLER CONDITIONS WITH SCATTERED RAIN CHANCES ARRIVE EARLY
NEXT WEEK. DETAILS ON THE EXACT EXTENT OF THE COOLDOWN AND
LOCATION OF THE HIGHEST RAIN CHANCES REMAIN UNCERTAIN AT THIS
TIME.
SHORT TERM /THROUGH FRIDAY/
ISSUED AT 101 PM CDT THU SEP 17 2026
SYNOPTIC AND MESOSCALE OVERVIEW:
BROAD RIDGING CONTINUES TO OVERSPREAD THE CENTRAL AND EASTERN
CONUS TODAY, WITH A QUASI-STATIONARY FRONT DRAPED ACROSS
NORTHERN MISSOURI. DEW POINTS ARE IN THE UPPER 60S TO NEAR 70
DEGREES AS TEMPERATURES RISE INTO THE MID 90S.
HEAT ADVISORY:
THE COMBINATION OF HIGH TEMPS AND DEW POINTS WILL ONCE AGAIN
PRODUCE AFTERNOON HEAT INDEX VALUES BETWEEN 100-105 DEGREES
TODAY AND TOMORROW. WITH CONSECUTIVE DAYS OF 100+ HI, WE HAVE
MAINTAINED THE HEAT ADVISORY AREAWIDE.
ISOLATED STORMS TODAY AND TOMORROW:
A FAIRLY STAGNANT ENVIRONMENT SUGGESTS PERSISTENCE FORECASTING
WILL BE A RELIABLE METHOD TODAY. THAT IS, ISOLATED TO WIDELY
SCATTERED CONVECTION LOOKS TO INITIATE ACROSS PORTIONS OF
SOUTHEAST AND SOUTH-CENTRAL MISSOURI THIS AFTERNOON AND EVENING
IN RESPONSE TO DIURNAL HEATING AND WEAK CAPPING (~25 J/KG)
WITHIN A ZONE OF WEAK FORCING. STEEP LOW-LEVEL LAPSE RATES BUT
MODEST VERTICAL TOTALS SUGGEST A FEW OF THE STRONGER PULSE
STORMS WILL BE CAPABLE OF DOWNBURST WINDS OF 50 TO 60 MPH, BUT
MOST IF NOT ALL ACTIVITY SHOULD REMAIN SUB-SEVERE. IN FACT, MOST
CAMS ARE SLIGHTLY LESS BULLISH IN CONVECTIVE INITIATION TODAY
THAN THEY WERE YESTERDAY. THUS, POPS HAVE BEEN LIMITED TO
20-25%.
BY FRIDAY, MODELS SHOW SOME SLIGHTLY DRIER AIR CREEPING INTO FAR
SOUTHERN MISSOURI. THIS DRIER AIR WILL CONFINE THE POP FOOTPRINT
TO PORTIONS OF CENTRAL MISSOURI. MOST AREAS WILL REMAIN DRY
OTHERWISE.
LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/
ISSUED AT 101 PM CDT THU SEP 17 2026
HIGHER RAIN CHANCES LATE SATURDAY THRU MONDAY:
GLOBAL MODELS DEPICT A BROAD MID-LEVEL SHORTWAVE FINALLY
TRANSLATING EAST THROUGH THE PLAINS AND INTO THE MIDWEST
SATURDAY INTO SUNDAY. THE LATEST SUITE OF GUIDANCE HAS CONTINUED
ITS SLOWER/LATER TREND WITH THE PASSAGE OF THE ATTENDANT
SURFACE FRONT THROUGH MISSOURI SOMETIME LATE SATURDAY NIGHT INTO
SUNDAY. THE INCREASED LIFT AND MODEST SHEAR ALONG THIS FRONT
WILL AID IN CONVECTIVE INITIATION LIKELY IN THE FORM OF LOOSELY
ORGANIZED CLUSTERS. THE BEST RAIN CHANCES WILL BE ACROSS CENTRAL
MISSOURI, WITH DECREASING CHANCES AS YOU LOOK SOUTH WHERE DRIER
AIR WILL BE PRESENT. DUE TO THE SLOW NATURE OF THE FRONT, RAIN
CHANCES WILL PERSIST THROUGH MONDAY AFTERNOON, BUT ALL DAY
WASHOUTS ARE NOT EXPECTED.
NBM PROBABILISTIC RAINFALL (SAT NIGHT THRU MON):
>0.10 INCH: 50-70%
>0.25 INCH: 40-60%
>1.00 INCH: 10-30%
HEAT THROUGH AT LEAST SATURDAY:
THERE IS MEDIUM TO HIGH CONFIDENCE IN CONTINUED AFTERNOON HEAT
INDEX VALUES REACHING NEAR 100 DEG THROUGH AT LEAST SATURDAY,
HENCE THE HEAT ADVISORY THROUGH 8 PM SATURDAY EVENING. IF THE
AFOREMENTIONED COLD FRONT REALLY SLOWS DOWN AS IT PASSES THROUGH
MISSOURI, OR IF CONVECTION/CLOUD COVER IS NOT QUITE AS
WIDESPREAD AS GLOBAL MODELS SUGGEST, THEN AN EXTENSION OF THE
ADVISORY MAY BE NEEDED ACROSS SOUTHERN MISSOURI WHERE
TEMPERATURES WILL REMAIN ABNORMALLY HOT. CONFIDENCE IS NOT HIGH
ENOUGH TO MAKE THAT DECISION AT THIS POINT, HOWEVER.
COOLER CONDITIONS EARLY NEXT WEEK:
THERE IS HIGH CONFIDENCE THAT COOLER TEMPERATURES WILL ARRIVE
NEXT WEEK. WHAT IS LESS CERTAIN IS EXACTLY HOW MUCH COOLER THESE
TEMPERATURES WILL END UP BEING. ENSEMBLES CONTINUE TO DISAGREE
IN JUST HOW FAR THE UPPER-LEVEL TROUGH DIGS AND HOW MUCH THE
RIDGE RETREATS; INDEED, NBM TEMPERATURE INTERQUARTILE SPREADS
INCREASE TO 7-9 DEGREES BY MONDAY.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 600 PM CDT THU SEP 17 2026
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. SCATTERED CLOUDS
WITH BASES 6-8KFT WILL DISSIPATE BY 01-02Z. THE ISOLATED SHOWER
AND THUNDERSTORM ACTIVITY ASSOCIATED WITH THESE CLOUDS IS NOT
EXPECTED TO IMPACT TAF SITES DUE TO OUTFLOW STABILIZING THE
ENVIRONMENT AROUND THE TERMINALS, BUT STORMS WILL BE SCATTERED
ACROSS THE REGION FOR THE NEXT 1-2 HOURS. AFTER THAT, ONLY
FORECAST CHANGE OF NOTE IS MORE SOUTHERLY WINDS GRADUALLY
SHIFTING IN OVERNIGHT.
CLIMATE
ISSUED AT 326 AM CDT THU SEP 17 2026
RECORD HIGH TEMPERATURES:
SEPTEMBER 17:
KSGF: 96/1953
KJLN: 95/1953
KVIH: 97/1953
KUNO: 97/1953
SEPTEMBER 18:
KSGF: 95/2019
KJLN: 97/2022
KVIH: 95/1953
KUNO: 96/1972
SEPTEMBER 19:
KSGF: 96/1954
KJLN: 99/2024
KUNO: 97/1954
SEPTEMBER 20:
KSGF: 97/1954
KJLN: 99/1954
KVIH: 95/1954
KUNO: 97/1954
SEPTEMBER 21:
KUNO: 95/1955
RECORD HIGH MINIMUM TEMPERATURES:
SEPTEMBER 17:
KSGF: 73/1978
SEPTEMBER 18:
KSGF: 74/1931
SEPTEMBER 19:
KSGF: 73/1931
SEPTEMBER 20:
KSGF: 74/2018
SEPTEMBER 21:
KSGF: 73/1931
SGF WATCHES/WARNINGS/ADVISORIES
KS...HEAT ADVISORY UNTIL 8 PM CDT SATURDAY FOR KSZ073-097-101.
MO...HEAT ADVISORY UNTIL 8 PM CDT SATURDAY FOR MOZ055>058-066>071-
077>083-088>098-101>106.
SHORT TERM...DIDIO
LONG TERM...DIDIO
AVIATION...CAMDEN
CLIMATE...NELSON
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