000
FXUS63 KABR 181810 AAB
AFDABR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
110 PM CDT SAT MAY 18 2013

.UPDATE...
THINGS HAVE QUIETED DOWN LATE THIS MORNING/EARLY THIS AFTERNOON AS
ONE SHORT-WAVE /AND ASSOCIATED RAIN AREA/ HAS PUSHED OUT OF THE
CWA AND WE WAIT FOR THE NEXT SHORT-WAVE TO ARRIVE. THE CIRRUS
DEBRIS CLOUD SHIELD THAT HAS BEEN OVER MUCH OF THE CWA SINCE EARLY
THIS MORNING IS DISSIPATING...SO SHOULD BEGIN TO SEE THE
INSTABILITY PICKING UP OVER THE NEXT SEVERAL HOURS AS DAYTIME
HEATING TAKES OVER. NO NOTEWORTHY CHANGES MADE TO THE TODAY PERIOD
FORECAST.


&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY

AN AREA OF LOW PRESSURE WILL SLOWLY MOVE THROUGH SD. ALONG AND
AHEAD OF THE TROF AXIS THERE IS ABUNDANT LOW LEVEL MOISTURE WITH A
DECENT 25 TO 30 KT LLJ. A SERIES OF EMBEDDED H7 AND H5 SHORTWAVES
WILL ALSO HELP AMPLIFY CONVECTIVE POTENTIAL ALONG AND EAST OF A
LINE FROM ABERDEEN TO PIERRE. SOME OF THE CONVECTION CURRENTLY
ONGOING IS EXPECTED TO LINGER INTO THE MID MORNING HOURS IN THE
NORTH TODAY. THERE MAY BE SOME STRATUS CIG DEVELOPMENT IN THE WAKE
OF OVERNIGHT AND EARLY MORNING ACTIVITY THAT WILL INHIBIT
CONVECTIVE DEVELOPMENT TODAY. THINKING THAT ANY LOWER CIGS WILL
ERODE BY AFTERNOON. SOME TSTORMS WILL THEN BE POSSIBLE DOWN NEAR
KPIR AND AREAS AROUND I-90. INSTABILITY INCREASES BETWEEN 03Z AND
09Z ALONG THE COTEAU WHERE BULK SHEAR GROWS TO AROUND 45 KTS. CAPE
WILL BE ABUNDANT AT AROUND 2500 TO 3500 J/KG THROUGH THE DAY.
LARGE HAIL WILL BE THE PRIMARY CONCERN.

RAIN AND TSTORM CHANCES WILL CONTINUE SUNDAY AND MONDAY AS THE SFC
LOW OCCLUDES OVER MN AND THE UPPER TROF MOVES EAST...CREATING A
FAIRLY WELL STACKED LOW PRESSURE SYSTEM. HIGH PWATS WILL MEAN THE
CHANCE FOR HEAVY RAIN. GREATEST CHANCES FOR INSTABILITY IN TSTORMS
WILL CONTINUE AHEAD OF THE LOW...SO SEVERE TSTORMS STILL A
POSSIBILITY SUNDAY MORNING ACROSS EASTERN SD AND WEST CENTRAL MN.


.LONG TERM...MONDAY NIGHT THROUGH FRIDAY

EXTENDED MODEL SOLUTIONS AGREE FAIRLY WELL ACROSS THE CONUS
THROUGH THE FORECAST PERIOD. THE PERIOD BEGINS WITH A CLOSED UPPER
LEVEL LOW PRESSURE SYSTEM SITUATED OVER THE EASTERN DAKOTAS AND
WESTERN MINNESOTA. THIS SYSTEM WILL BRING PERIODS OF SHOWERS
THROUGH AT LEAST WEDNESDAY EVENING BEFORE DEPARTING THE REGION.
LIMITED HEATING DUE TO EXTENSIVE CLOUD COVER WILL KEEP
TEMPERATURES VERY COOL WITH HIGHS SOME 10 TO 15 DEGREES BELOW
NORMAL ON TUESDAY AND WEDNESDAY. UPPER LEVEL RIDGING WILL
EVENTUALLY MOVE INTO THE REGION BY THURSDAY WITH WARMER AND DRIER
CONDITIONS PREVAILING THROUGH THE REST OF THE PERIOD.


&&

.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS

GOOD VFR SHOULD BE THE RULE OF THE DAY AND RIGHT ON INTO
TONIGHT...UNTIL SHOWERS AND THUNDERSTORMS DEVELOP AND MOVE THROUGH
THE FORECAST AREA. PRESENTLY SOME FORM OF VICINITY SHOWER OR
VICINITY THUNDERSTORM MENTION IS IN ALL FOUR TAFS FOR WHEN THE
HIGHEST PROBABILITY OF PRECIPITATION IS CURRENTLY ANTICIPATED.
EXPECT SUB-VFR VISBY/CIG CONDITIONS IN MODERATE TO HEAVY RAINFALL
TO ACCOMPANY SHOWERS AND STORMS OVERNIGHT. THERE COULD ALSO BE
SOME HAIL AND STRONG WINDS TO DEAL WITH TONIGHT. BEHIND THE
PRECIPITATION...SUB-VFR BKN/OVC STRATUS IS EXPECTED TO FORM AND
STAY PUT LATE TONIGHT INTO THE MORNING HOURS ON SUNDAY.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&

$$
UPDATE...DORN
SHORT TERM...WISE
LONG TERM...SD
AVIATION...DORN

WEATHER.GOV/ABERDEEN