143
FXUS63 KFSD 101706
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1206 PM CDT WED AUG 10 2022
SHORT TERM
(TODAY AND TONIGHT)
ISSUED AT 349 AM CDT WED AUG 10 2022
A SOMEWHAT MILD, BUT RELATIVELY PLEASANT START TO THE DAY. SKIES
ARE MOSTLY CLEAR, WITH TEMPERATURES IN THE 60S TO LOWER 70S. WINDS
ARE LIGHT, WITH ANY PREVAILING DIRECTION BEING SOUTHEASTERLY.
STILL CAN'T RULE OUT SOME PATCHY FOG THROUGH THIS MORNING, MAINLY
IN RIVER VALLEYS AND OTHER LOW LYING AREAS.
FOR THE REST OF THE DAY, EXPECT QUIET CONDITIONS AS SURFACE HIGH
PRESSURE REMAINS TO THE EAST. THIS KEEPS WINDS RELATIVELY LIGHT,
ESPECIALLY EAST OF I-29, WITH SLIGHTLY MORE NOTICEABLE BREEZES TO
THE WEST OF THE JAMES RIVER (THANKS TO A SUBTLY TIGHTER SURFACE
PRESSURE GRADIENT AND A COUPLE OF KNOTS STRONGER FLOW ALOFT MIXING
TO THE SURFACE). CLOUD COVER WILL BE SPARSE AS MOISTURE THROUGH
THE ATMOSPHERE REMAINS LACKING. TEMPERATURES CLIMB INTO THE MID
80S ACROSS THE NORTHEASTERN CWA, WITH READINGS IN THE MID/UPPER
90S SOUTH OF THE BOUNDARY TOWARD THE MO RIVER VALLEY.
RIDGE ALOFT CONTINUES TO BUILD, WITH RIDGE AXIS SLIDING A BIT
SOUTHEASTWARD THROUGH LATE TODAY AND TONIGHT. CLOUDS INCREASE
WITH INCREASING MOISTURE ALOFT. A SUBTLE WAVE/VORT MAX PAIRED WITH
AREAS OF FRONTOGENESIS (F-GEN) SLIDING THROUGH THE RIDGE ALONG
WITH THE INCREASE IN MOISTURE COULD LEAD TO SOME SHOWERS ACROSS
THE EASTERN PORTIONS OF THE FORECAST AREA. BROADER SCALE MODELS
GENERALLY AGREE IN FOCUSING THIS ACTIVITY OVERNIGHT ACROSS
SOUTHWESTERN MN AND NORTHWESTERN IA, BUT DISAGREE ON THE WESTWARD
EXTENT. VARIANCE IS ALSO APPARENT IN THE HI-RES GUIDANCE, WITH MOST
FOCUSING PRECIP IN THE EAST BUT DIFFERING ON THE WESTWARD EXTENT
AND TIMING. MODELS SHOW ANOTHER AREA OF VORTICITY ACROSS NORTHERN
NE; HOWEVER, THIS FEATURE LOOKS TO STAY FAR ENOUGH TO THE SOUTH
AND DRY ENOUGH TO PRECLUDE MENTIONABLE POPS ALONG THE SD/NE
BORDER. REGARDLESS, INSTABILITY REMAINS LOW, AROUND 500 J/KG OR
LESS OF CAPE, SO WOULD NOT BE SURPRISED TO SEE MORE SHOWERS THAN
THUNDERSTORMS (ALTHOUGH ISOLATED RUMBLES OF THUNDER ARE CERTAINLY
POSSIBLE). TEMPERATURES STAY ON THE WARMER SIDE WITH WAA, AND DID
BUMP UP TEMPS A DEGREE OR TWO (MAINLY EAST OF I-29) AS MODELS
INDICATE A LOCALIZED STRONGER PUSH OF WAA, AND EXPECT IT TO BE
ABLE TO OVERCOME THE INCREASE IN CLOUDINESS AND ANY POTENTIAL
PRECIPITATION. LOWS REMAIN IN THE 60S.
LONG TERM
(THURSDAY THROUGH TUESDAY)
ISSUED AT 349 AM CDT WED AUG 10 2022
SIMILAR TO WEDNESDAY NIGHT, MODELS THROUGH MID THURSDAY MORNING
INDICATE A SECONDARY WAVE/VORT MAX AND AREA OF F-GEN, ALTHOUGH
THIS ONE MAY SWING THROUGH THE JAMES VALLEY. COULD SEE AT LEAST
ONE MORE WAVE GRAZE OUR SOUTHWESTERN MN COUNTIES THROUGH THURSDAY
NIGHT. LIMITED POPS THOUGH TO MOSTLY BELOW MENTION THROUGH
THURSDAY EVENING OUTSIDE OF SOUTHWESTERN MN/NORTHWESTERN IA, WHERE
MOISTURE LOOKS TO BE THE MOST PREVALENT WITH THE NEXT VORT MAX.
WARMER TEMPS ON THURSDAY WITH INCREASING SOUTHERLY SURFACE FLOW.
THIS COMBINED WITH THE LIKELY LACK OF PRECIP AND DRYING FUELS LEADS
TO ELEVATED FIRE DANGER ACROSS SOUTH CENTRAL SD. BOUNDARY
REMAINING IN PLACE KEEPS A WIDE GRADIENT OF TEMPERATURES OVER THE
AREA, IN THE UPPER 70S/LOWER 80S IN SOUTHWESTERN MN TO THE
MID/UPPER 90S THROUGH THE MO VALLEY. COULD POSSIBLY SEE SOME AREAS
APPROACH 100 ACROSS SOUTH CENTRAL SD, DEPENDING ON WHERE EXACTLY
THE 925MB BOUNDARY ENDS UP AND HOW EFFICIENT MIXING IS.
RIDGE STAYS IN PLACE THROUGH THE WEEKEND, AS TROUGH/LOW PRESSURE
GRIPS THE NORTHEASTERN CONUS. BOUNDARY REMAINS IN PLACE THROUGH
FRIDAY SHOVED OUT OF THE WAY BY 850MB LOW LATE FRIDAY AND SURFACE
LOW PRESSURE SLIDING ACROSS DURING THE END OF THE WEEK/START OF THE
WEEKEND. ADDITIONALLY, THIS PATTERN ALOFT IS FAVORABLE FOR CONTINUED
RIDGE RIDER WAVES TO SWING THROUGH, WITH MODELS AGREEING ON THE
POTENTIAL FOR A COUPLE OF MORE DEFINED MID LEVEL WAVES, BUT REMAIN
FUZZY ON THE DETAILS. TEMPERATURES WILL CONTINUE TO RANGE FROM NEAR
80 TO THE MID/UPPER 90S. MOSTLY DRY WEATHER IS EXPECTED, WITH SHOWER
AND STORM CHANCES RELYING ON THE TIMING OF WAVES AND MOISTURE.
INSTABILITY OVERALL REMAINS LACKING, SO SEVERE WEATHER CHANCES
REMAIN VERY LOW.
ENSEMBLE TRENDS THROUGH THE WEEKEND CONTINUE TO KEEP THE HIGHEST
POTENTIAL FOR 0.10" OR MORE OF RAIN IN ANY 24 HOUR PERIOD NORTH
AND EAST OF SIOUX FALLS, WITH THE ECMWF ENSEMBLE REMAINING MUCH
MORE OPTIMISTIC THAT A FEW FOLKS IN OUR SOUTHWESTERN MN COUNTIES
MAY POSSIBLY SEE SOME RAIN. PROBABILITIES FOLLOW A SIMILAR TREND,
FOR MEASURABLE PRECIP (I.E. 0.01" OR MORE) IN A 24 HOUR PERIOD
THROUGH SUNDAY, BUT REMAIN VERY LOW, WITH FOLKS ACROSS SOUTH
CENTRAL SD AND THE MO VALLEY TOWARD SIOUX CITY, IA LIKELY MISSING
OUT. AS WITH THURSDAY, WILL NEED TO WATCH FRIDAY AND POSSIBLY
INTO THE WEEKEND FOR ELEVATED FIRE DANGER, ESPECIALLY ACROSS SOUTH
CENTRAL SD INTO THE MO VALLEY.
EVOLUTION OF THE PATTERN EARLY TO MID NEXT WEEK BECOMES VERY
CONVOLUTED, AS MODELS DIFFER ON THE TRAJECTORY OF ADDITIONAL, MORE
ROBUST WAVES BOTH ACROSS THE RIDGE AND THROUGH THE LOW PRESSURE
PARKED OVER THE NORTHEAST. TEMPERATURES LOOK TO BE NEAR TO POSSIBLY
JUST BELOW AVERAGE.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1204 PM CDT WED AUG 10 2022
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. A STATIONARY FRONT
WILL KEEP NORTHEASTERLY OR SOUTHEASTERLY LIGHTER WINDS PREVAILING
THROUGH THURSDAY MORNING. MID TO HIGH CLOUDS WILL STREAM IN
OVERNIGHT FROM THE NORTH WITH SHOWERS POSSIBLE IN SOUTHWEST MN.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
SHORT TERM...SG
LONG TERM...SG
AVIATION...BP
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