005
FXUS63 KFSD 071118
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
618 AM CDT WED MAY 7 2025
KEY MESSAGES
- SLIGHTLY COOLER (ABOUT 5 DEGREES) TODAY WITH A 25 PERCENT
CHANCE OF AFTERNOON SHOWERS AND VERY ISOLATED THUNDERSTORMS
ALONG THE HIGHWAY 20 CORRIDOR. IF SHOWERS DEVELOP, RAINFALL
AMOUNTS WILL BE LIGHT - LESS THAN A TENTH OF AN INCH.
- THURSDAY THROUGH SATURDAY CONTINUES TO BE WARM AND DRY WITH
HIGHS FROM THE UPPER 70S INTO THE MID 80S.
- VERY WARM AND BREEZY SUNDAY INTO THE NEXT WEEK. EXPECT DAILY
HIGHS IN THE 80S WITH SOME LOCATIONS APPROACHING 90 DEGREES.
ELEVATED FIRE CONCERNS ARE POSSIBLE SUNDAY INTO EARLY NEXT
WEEK.
DISCUSSION
ISSUED AT 256 AM CDT WED MAY 7 2025
CURRENTS THROUGH TONIGHT: MID AND HIGH CLOUDS CONTINUE TO STREAM
NORTH THIS MORNING FROM LOW PRESSURE TO OUR SOUTH. TEMPERATURES
REMAIN MILD THROUGH 3 AM, STILL IN THE MID 50S TO LOWER 60S,
ALTHOUGH WE'LL COOL INTO THE 50S BY DAYBREAK.
REX BLOCK REMAINS IN PLACE WITH THE MID/UPPER LEVEL LOW SLIDING
ACROSS THE SOUTHERN PLAINS AND HIGH PRESSURE TO OUR NORTH. COULD SEE
SOME HIGH BASED SPRINKLES TOWARD THE US HWY 20 CORRIDOR THIS
AFTERNOON WITH SOME WEAK (LESS THAN 200 J/KG FROM MOST MODELS)
INSTABILITY AND CONVERGENCE. THERE'S SOME WEAK VORTICITY AND WAA
ALOFT WITH AN UPPER LEVEL JET STREAK AS WELL. HOWEVER, GIVEN THE DRY
SUB CLOUD LAYER BELOW 7KFT, THINK PRECIPITATION WILL STRUGGLE AND
THUS HAVE KEPT PRECIP CHANCES 25% OR LESS. IF WE'RE ABLE TO SNEAK
OUT ANY PRECIPITATION, AMOUNTS WILL BE LIGHT - LESS THAN A TENTH OF
AN INCH. CHANCES FOR MORE THAN A TENTH ARE VERY LOW (LESS THAN 20%),
WITH CHANCES FOR MEASURABLE PRECIP MAXING OUT AROUND 65%.
ALTHOUGH WE'LL SEE MORE CLOUD COVER AROUND TODAY WITH THE LOW
PRESSURE TO OUR SOUTH, HAVE INCREASED HIGHS FROM PREVIOUS BY A
COUPLE OF DEGREES - STILL IN THE 70S TO LOWER 80S. BREEZIER TODAY
WITH NORTHEAST WINDS 10-15 MPH AND GUSTS TO 25 MPH. LOWS TONIGHT IN
THE MID 40S TO LOWER 50S.
THURSDAY: MESSIER FLOW FOR THURSDAY AS THE AFOREMENTIONED LOW
BECOMES CUT OFF IN THE MIDWEST. SIMILAR TEMPERATURES TO WEDNESDAY,
ALTHOUGH WARMER WEST OF THE JAMES RIVER WHERE SOUTHERLY FLOW
PREVAILS. HIGHS IN THE MID 70S TO LOWER 80S. NOT QUITE AS BREEZY
WITH WINDS BECOMING SOUTHERLY TOWARD THE END OF THE DAY. LOWS IN THE
40S.
FRIDAY-THE WEEKEND: SURFACE LOW PRESSURE SLIDES THROUGH THE REGION
FRIDAY - NOT EXPECTING ANYTHING IN THE WAY OF PRECIPITATION GIVEN
THE LACK OF MOISTURE. ALOFT, THE CUT OFF LOW CONTINUES TO MEANDER TO
OUR SOUTHEAST. RIDGING BUILDS INTO THE REGION THROUGH THE WEEKEND,
WITH A COUPLE OF WEAK SHORT WAVES MOVING THROUGH THE PATTERN. THIS
RESULTS IN CONTINUED DRY AND WARMER THAN AVERAGE CONDITIONS. HIGHS
IN THE 80S, ABOUT 10 DEGREES ABOVE NORMAL. BY SUNDAY, ENSEMBLE
PROBABILITY OF HIGHS OVER 80 IS MODERATE TO HIGH (OVER 40%) FOR
ALMOST THE ENTIRE FORECAST AREA. LOWS MOSTLY IN THE 50S. DRY AIR,
WARM TEMPERATURES, AND BREEZY SOUTHERLY WINDS SUNDAY MAY LEAD TO
AREAS OF ELEVATED FIRE DANGER DESPITE RECENT GREEN UP OF FUELS.
SOUTHWEST WINDS ON SUNDAY COULD GUST OVER 40 MPH, ESPECIALLY WEST OF
THE JAMES RIVER.
EARLY NEXT WEEK: CUT OFF LOW WOBBLES BACK INTO THE MIDWEST EARLY
NEXT WEEK. BACK TO THE WEST, MID/UPPER LEVEL TROUGHING DEVELOPS,
SENDING AT LEAST ONE SHORT WAVE INTO THE PLAINS AHEAD OF THE TROUGH
AND SURFACE LOW EJECTING MID WEEK. THIS COULD BRING SOME CHANCES FOR
RAIN AND STORMS, BUT CONFIDENCE IS LOW GIVEN MODEL VARIABILITY IN
TIMING/LOCATION.
MAIN IMPACTS DURING THIS TIME WILL BE THE CONTINUED ABOVE AVERAGE
TEMPERATURES IN THE 80S TO NEAR 90. STRONG SOUTHERLY WINDS, WARM
TEMPERATURES, AND LOW HUMIDITY VALUES WILL KEEP THE THREAT OF
ELEVATED FIRE DANGER IN PLAY. LOWS IN THE 50S TO LOWER 60S.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 614 AM CDT WED MAY 7 2025
VFR CONDITIONS PREVAIL THROUGH THE PERIOD, WITH MID AND HIGH
CLOUDS AROUND THE REGION. LOW (LESS THAN 25%) CHANCES FOR
SHOWERS AND THUNDERSTORMS ALONG THE US HIGHWAY 20 CORRIDOR.
ALTHOUGH CONFIDENCE IS LOW, DID MAINTAIN THE PROB30 GROUP AT
KSUX. CLOUD BASES ARE EXPECTED TO BE AROUND 8KFT, SO COULD SEE
SOME VIRGA IN THE AREA IF PRECIPITATION IS ABLE TO DEVELOP. THE
REST OF THE AREA REMAINS DRY.
OTHERWISE, WINDS VARY FROM NORTHEAST TO EAST THROUGH THE PERIOD
WITH GUSTS AROUND 20 KNOTS THIS AFTERNOON AND EVENING.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...SG
AVIATION...SG
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