557
FXUS63 KABR 130853
AFDABR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
353 AM CDT TUE AUG 13 2013
.SHORT TERM...TODAY THROUGH THURSDAY
THE CURRENT SURFACE PRESSURE PATTERN FEATURES A HIGH PRESSURE
RIDGE ACROSS EASTERN SOUTH DAKOTA...ALLOWING FOR LIGHT SURFACE
WINDS AND CLEAR SKIES. WHEREAS A WEAK LEE OF THE ROCKIES TROUGH
HAS RESULTS IN RETURN FLOW WINDS AND A MOISTURE GRADIENT ACROSS
THE WESTERN HALF OF THE STATE. A FEW THUNDERSTORMS HAVE DEVELOPED
ALONG THE GRADIENT THIS MORNING. NOT SURE THAT THEY WILL MAKE EAST
INTO OUR CWA...BUT LEFT A SLIGHT CHANCE MENTION IN FOR OUR
SOUTHWEST CWA TO ACCOUNT FOR ANY STRAY SHOWERS OR THUNDERSTORMS.
THIS SURFACE PATTERN REMAINS RELATIVELY UNCHANGED THROUGH
WEDNESDAY. SO A SIMILAR SET UP IS EXPECTED LATER THIS AFTERNOON
INTO WEDNESDAY MORNING...WHERE A FEW SHOWERS AND THUNDERSTORMS
WILL DEVELOP ALONG THE MOISTURE GRADIENT...MAINLY AFFECTING THE
SOUTHWEST AND WESTERN CWA. BY WEDNESDAY AFTERNOON A PRETTY DECENT
UPPER SHORTWAVE WILL DROP THROUGH NORTHWEST FLOW ALOFT. THIS WILL
BRING ADDITIONAL CHANCES FOR THUNDERSTORMS WEDNESDAY
AFTERNOON...AGAIN...MAINLY AFFECTING THE WESTERN AND SOUTHERN CWA.
A DECENT INSTABILITY GRADIENT SETS UP OVER THIS REGION...WITH
MODEST BULK SHEAR PRESENT. THIS COULD RESULT IN AN ISOLATED STRONG
OR SEVERE STORM...BUT IT DOESNT APPEAR TO BE ANYTHING WIDESPREAD
AT THIS TIME.
BY THURSDAY...MODELS INDICATE RAPIDLY RISING 500 MB HEIGHTS AS AN
UPPER RIDGE SHIFTS OVERHEAD. AND AS SUCH...TEMPERATURES WILL BE
RISING...AND BELOW NORMAL TEMPERATURES ON TUESDAY AND WEDNESDAY
WILL SHIFT TO MORE SEASONAL TEMPERATURES /IN THE 80S/ BY THURSDAY.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
THE MODELS ALL AGREE REAL WELL THROUGH THE LONG TERM IN WARMING IT
UP ACROSS THE REGION AS 50H HEIGHTS RISE FROM AROUND 581 ON
THURSDAY NIGHT TO AROUND 587 BY SUNDAY AFTERNOON. 70H TEMPERATURES
ALSO WARM FROM AROUND 5 TO 7C ON THURSDAY NIGHT TO 11 TO 15C BY
SUNDAY AFTERNOON. THE EC AND GFS GUIDANCE SHOW THIS WARM UP
ACCORDINGLY FROM THE UPPER 70S TO THE MID 80S ON FRIDAY INTO THE
MID 80S TO AROUND 90 DEGREES OR HIGHER FOR SATURDAY...SUNDAY AND
MONDAY. WOULD NOT DOUBT THESE FORECAST HIGH TEMPERATURES WILL BE
RAISED A FEW DEGREES HIGHER AS WE GET CLOSER TO THIS TIME.
ALSO...THE HUMIDITY WILL BE INCREASING SOME ON SOUTH WINDS THROUGH
THE PERIOD. THE ONLY CHANCES OF STORMS APPEAR TO BE
SUNDAY...SUNDAY NIGHT AND INTO MONDAY MORNING AS THE MODELS ALL
AGREE WELL THAT A SHORT WAVE TROUGH WILL COME ACROSS THE REGION
DURING THIS TIME.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA OVERNIGHT AND THROUGH
THE DAY TUESDAY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...SERR
LONG TERM...MOHR
AVIATION...MOHR
WEATHER.GOV/ABERDEEN