040
FXUS63 KFSD 021745
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1245 PM CDT THU OCT 2 2025
KEY MESSAGES
- WELL ABOVE NORMAL TEMPERATURES CONTINUE THROUGH SATURDAY. A
FEW RECORD HIGH TEMPERATURES AND WARM LOW TEMPERATURES ARE
POSSIBLE OVER THE WEEKEND.
- CONTINUED DRY CONDITIONS AND BREEZY TO WINDY AFTERNOONS LEAD
TO LOCALLY ELEVATED FIRE WEATHER CONCERNS AS FIRE FUELS
CONTINUE DRYING. MORE WIDESPREAD ELEVATED FIRE DANGER IS
EXPECTED SATURDAY.
- RAIN CHANCES (LESS THAN 50%) RETURN SATURDAY NIGHT INTO SUNDAY
MAINLY ALONG AND WEST OF THE JAMES RIVER VALLEY, ALTHOUGH
GUIDANCE CONTINUES TO TREND DOWNWARD. CONFIDENCE IS LOW, BUT
AN ISOLATED STRONGER STORM IS POSSIBLE SATURDAY AFTERNOON AND
EVENING.
- NEAR NORMAL TEMPERATURES RETURN WITH LOW (LESS THAN 20%) RAIN
CHANCES EARLY TO MID NEXT WEEK.
DISCUSSION
ISSUED AT 326 AM CDT THU OCT 2 2025
NOW THROUGH TONIGHT: HAVE SEEN A FEW SHOWERS/THUNDERSTORMS EARLY
THIS MORNING EAST OF I-29; HOWEVER, COVERAGE HAS DIMINISHED AND
EXPECT MORE ISOLATED ACTIVITY THROUGH DAYBREAK. MOST OF THE AREA
REMAINS DRY.
LESS BREEZY TODAY WITH WEAK SURFACE HIGH PRESSURE OVERHEAD AND LESS
STRONG WINDS ALOFT FOR US TO MIX INTO. MID AND UPPER LEVEL RIDGING
BEGINS TO BUILD TODAY AND TONIGHT. HIGHS WARM INTO THE MID 80S WITH
MOSTLY SUNNY SKIES. LIGHTER WINDS TEMPER WIDESPREAD FIRE CONCERNS,
BUT CAUTION SHOULD STILL BE TAKEN IN AREAS WHICH ARE DRYING OUT MORE
QUICKLY WITH OCCASIONAL GUSTS AROUND 20 MPH. LOWS TONIGHT DROP
INTO THE UPPER 50S AND LOWER 60S WITH MOSTLY CLEAR SKIES.
FRIDAY-SATURDAY: MID/UPPER LEVEL RIDGING CONTINUES TO SLIDE EAST
THROUGH THE FIRST PART OF THE WEEKEND, WITH TROUGHING DEEPENING OVER
THE WESTERN CONUS. AT THE SURFACE, LOW PRESSURE BEGINS TO MOVE EAST
OUT OF THE ROCKIES IN TO WESTERN SD FRIDAY NIGHT. THIS PATTERN
ALLOWS FOR CONTINUED WAA AND SOUTHWESTERLY FLOW, KEEPING OUR
TEMPERATURES WELL ABOVE AVERAGE TO NEAR RECORD. GUIDANCE HAS BEEN
TRENDING STRONGER WITH THE LOW PRESSURE AND THE PRECEDING THERMAL
RIDGE. CONTINUED TO TREND THESE VALUES UP FROM THE POPULATED NBM
GUIDANCE, ESPECIALLY GIVEN THE IMPACTS OF THESE PARAMETERS ON FIRE
DANGER. FOR CONTEXT, TEMPERATURES AT MULTIPLE LOWER LEVELS OF THE
ATMOSPHERE ON FRIDAY AND THROUGH SATURDAY ARE IN THE TOP 1% WHEN
COMPARED TO CLIMATOLOGY FOR THIS TIME OF YEAR. RECORD HIGH
TEMPERATURES BOTH FRIDAY AND SATURDAY AND RECORD WARM LOW TEMPS ARE
IN JEOPARDY DURING THIS TIME WITH HIGHS IN THE UPPER 80S TO LOWER
90S AND LOWS IN THE UPPER 60S TO NEAR 70 FRIDAY NIGHT.
WITH THE GUIDANCE TRENDING STRONGER WITH THE LOW, NBM WINDS LIKELY
REMAIN TOO LOW AND HAVE INCREASED ACCORDINGLY. FRIDAY AND SATURDAY
ARE BOTH EXPECTED TO BE BREEZY TO WINDY IN RESPONSE TO BOTH THE
TIGHTENING OF THE SURFACE PRESSURE GRADIENT AND MIXING INTO STRONGER
FLOW ALOFT. GENERALLY, WINDS FRIDAY WEST OF I-29 WILL GUST AROUND 30
TO 35 MPH. MOST OF THE AREA SATURDAY WILL SEE GUSTS 35-40 MPH. DID
AGAIN INCREASE WINDS FROM THE NBM, AND ADDITIONAL INCREASES MAY BE
NEEDED.
THIS COMBINATION OF STRONG WINDS AND WELL ABOVE TO NEAR RECORD
TEMPERATURES ALONG WITH DRYING FUELS LEAD TO ELEVATED FIRE DANGER.
GREATEST CONCERN IS SATURDAY, WITH MORE WIDESPREAD ELEVATED FIRE
DANGER DUE TO THOSE STRONGER WINDS. HUMIDITY VALUES SHOULD REMAIN
ABOVE CRITICAL THRESHOLDS BUT CAUTION SHOULD BE USED TO PREVENT
FIRE START - ESPECIALLY ON SATURDAY.
SATURDAY LATE AFTERNOON-SUNDAY NIGHT: TROUGH, SURFACE LOW, AND COLD
FRONT WILL MOVE THROUGH THE NORTHERN PLAINS BY SATURDAY NIGHT
THROUGH SUNDAY. MODELS CONTINUE TRENDING THIS SYSTEM'S TRACK TO OUR
NORTH AND WEST, WHICH IF THIS VERIFIES, WOULD GREATLY LIMIT THE
POTENTIAL FOR RAIN OVER OUR AREA DURING THIS PERIOD - ESPECIALLY
EAST OF I-29. THIS SHIFT IS NOTABLE IN THE COMPARISON OF THE
PROBABILITY OF 0.01" OR MORE OF RAIN SATURDAY AFTERNOON TO SUNDAY
AFTERNOON. 01.00Z GUIDANCE SHOWS A 52% CHANCE OF EXCEEDANCE AT SIOUX
FALLS AND 76% AT HURON, WHILE THE 02.00Z GUIDANCE DROPS THOSE TO 40%
AND 65% RESPECTIVELY. THIS FITS WELL WITH THE DOWNWARD TREND (NORTH
AND WEST SHIFT) IN POPS OVER THE LAST 24 HOURS. THIS TRACK MAY STILL
SHIFT, BUT CONFIDENCE IN SEEING BENEFICIAL RAIN IS DECREASING.
THERE REMAINS SOME UNCERTAINTY IN THE TIMING OF THE FEATURES SUCH AS
THE SURFACE LOW AND THE UPPER LEVEL JET STREAK. BEST SHEAR AND
INSTABILITY STILL LOOK TO BE DISPLACED IN SPACE AND TIME; HOWEVER,
THERE MAY BE A BRIEF TIME WHERE THESE ALONG WITH LIFT FROM THE WAVE
FOR A COUPLE OF STRONGER STORMS (AS NOTED BY THE SPC DAY 3 OUTLOOK
AND SOME MACHINE LEARNING GUIDANCE). MAIN CONCERN WOULD BE STRONG
WIND GUSTS, GIVEN THE PATTERN, BUT LARGE HAIL CAN'T BE RULED OUT
WITH STEEPENING MID LEVEL LAPSE RATES. CONCERN WOULD BE IN THE LATE
AFTERNOON AND EVENING, ALTHOUGH THREAT COULD LINGER INTO THE LATE
EVENING AS THE LLJ STRENGTHENS.
MOST OF SUNDAY SHOULD BE DRY, ALTHOUGH THE US HWY 20 CORRIDOR MAY
SEE SOME LIGHT RAIN WITH A SOUTHERN TRACK MID LEVEL WAVE; CHANCES
ARE LOW (< 20%). TEMPERATURES WILL BE ON A COOLING TREND TOWARD
NORMAL BEHIND THE COLD FRONT. NORTHWESTERLY WINDS SUNDAY INTO SUNDAY
NIGHT REMAIN STRONG BEHIND THE FRONT WITH THE ROBUST CAA; THEREFORE
INCREASED WINDS/GUSTS DURING THIS TIME FROM THE NBM. MAY SEE SOME
CONTINUED GUSTS DURING THIS TIME TO 35-40 MPH.
MONDAY-WEDNESDAY: COOLER TEMPERATURES AND SURFACE HIGH PRESSURE
PREVAIL MONDAY WITH MOSTLY DRY CONDITIONS EXPECTED. TUESDAY, WE'LL
SEE A MID/UPPER LEVEL TROUGH AND SURFACE BOUNDARY SWING THROUGH THE
NORTHERN PLAINS BUT GUIDANCE VARIES IN TIMING AND TRACK. CHANCES OF
MEASURABLE PRECIPITATION ARE LOW TO MODERATE (LESS THAN 50% FOR
MOST OF THE AREA). HIGH PRESSURE RETURNS MID WEEK, FOLLOWING ANOTHER
PUSH OF CAA. NEAR NORMAL TO EVEN POSSIBLY BELOW AVERAGE TEMPERATURES
FINALLY RETURN, WITH HIGHS IN THE 60S AND LOWS IN THE LOWER/MID 40S.
AFTERNOONS MAY BE A TOUCH BREEZY, BUT LOWER TEMPERATURES AND RH
ABOVE CRITICAL THRESHOLDS SHOULD LIMIT WIDESPREAD FIRE CONCERNS.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1236 PM CDT THU OCT 2 2025
VFR CONDITIONS WILL PERSIST ACROSS THE AREA THIS TAF PERIOD.
TAKING A LOOK AT SATELLITE IMAGERY, CLEARER CONDITIONS PERSIST
THIS AFTERNOON WITH SLIGHTLY BREEZIER CONDITIONS EAST OF I-29.
EXPECT SOUTHWESTERLY WINDS TO GRADUALLY DECREASE BY THIS EVENING
WITH LIGHT AND VARIABLE WINDS RETURNING OVERNIGHT. LASTLY,
EXPECT THE BREEZIER CONDITIONS TO RETURN BY FRIDAY AFTERNOON
MAINLY ALONG AND WEST OF I-29 TO END THE TAF PERIOD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...SG
AVIATION...05
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