000
FXUS63 KUNR 230859
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
259 AM MDT THU MAY 23 2013

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 208 AM MDT THU MAY 23 2013

CURRENT SURFACE MAP PLACES HIGH PRESSURE RIDGE ACROSS THE EASTERN
DAKOTAS...WITH LEE SIDE TROF ACROSS MONTANA/WYOMING. LARGE UPPER
LOW SPINNING ACROSS THE PACIFIC NORTHWEST.

TIGHT PRESSURE GRADIENT ACROSS THE FORECAST AREA ALONG WITH
3-4MB/3HR PRESSURE FALLS ACROSS MONTANA WILL RESULT IN WINDY
CONDITIONS...ESPECIALLY ACROSS NORTHEAST WYOMING AND NORTHWEST
SOUTH DAKOTA. WIND GUSTS OF 45-50 MPH LIKELY. WITH UPPER LEVEL
SUBSIDENCE AND STRONG INVERSION...WILL BE DRY TODAY.

FOR TONIGHT...40-50KT LOW LEVEL JET IS LOCATED ACROSS WESTERN
SOUTH DAKOTA WHILE STRONG SHORTWAVE LIFTS THROUGH WESTERN WYOMING
INTO SOUTHERN MONTANA. 2-3C/HR 850-700MB THETA-E ADVECTION
DEVELOPS ACROSS CENTRAL SOUTH DAKOTA. WITH MUCAPE AROUND
250J/KG...A FEW THUNDERSTORMS POSSIBLE ACROSS SOUTH CENTRAL SOUTH
DAKOTA LATE TONIGHT. AS UPPER SHORTWAVE LIFTS INTO EASTERN MONTANA
EARLY FRIDAY MORNING...MODERATE Q-G FORCING PASSES THROUGH
WESTERN SOUTH DAKOTA. BEST CHANCE OF PRECIPITATION ON FRIDAY
SHIFTS EAST OF THE FORECAST EARLY IN THE DAY. HAVE TRIMMED BACK ON
POPS ACROSS WESTERN SOUTH DAKOTA DUE TO LACK OF INSTABILITY.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 208 AM MDT THU MAY 23 2013

UPPER LOW OVER THE PACIFIC NORTHWEST WILL GENERALLY REMAIN IN PLACE
OVER THE WEEKEND...WITH SOUTHWESTERLY FLOW ALOFT OVER OUR REGION. A
SERIES OF DISTURBANCES IN THIS FLOW WILL MOVE ACROSS THE NORTHERN
PLAINS OVER THE HOLIDAY WEEKEND...BRINGING DAILY CHANCES FOR SHOWERS
AND THUNDERSTORMS. LEE TROF/DRY LINE WILL GENERALLY REMAIN IN PLACE
ACROSS FAR EASTERN MT AND NORTHEASTERN WY DURING THE PERIOD...WITH
MOIST SOUTHEASTERLY FLOW AND INCREASING INSTABILITY TO THE EAST OF
THE TROF ACROSS THE DAKOTAS. THE THREAT FOR STRONG TO SEVERE
THUNDERSTORMS WILL BEGIN TO INCREASE ON SATURDAY OVER MOST OF THE
FORECAST AREA...WITH THE BETTER CHANCES STILL LOOKING TO BE ON
SUNDAY AND MONDAY. THE EXTENT OF THE SEVERE RISK WILL DEPEND ON THE
TIMING OF THESE DISTURBANCES...WHICH IS STILL UNCERTAIN AT THIS
POINT. CHANCES FOR THUNDERSTORMS WILL LIKELY CONTINUE INTO THE
MIDDLE OF NEXT WEEK AS GENERAL PATTERN CONTINUES. TEMPERATURES WILL
REMAIN ABOVE AVERAGE...WITH HIGHS IN THE 70S AND LOWER 80S ACROSS
THE AREA THROUGH EARLY NEXT WEEK.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT
ISSUED AT 208 AM MDT THU MAY 23 2013

MVFR/IFR CONDITIONS WILL PERSIST ACROSS MUCH OF NORTHEASTERN WY AND
SOUTHWESTERN SD THIS MORNING. PATCHY FOG IS ALSO POSSIBLE...
ESPECIALLY OVER THE HIGHER TERRAIN. GUSTY SOUTHEASTERLY WINDS WILL
DEVELOP ACROSS NORTHEASTERN WY AND WESTERN SD THIS MORNING AND
PERSIST THROUGH THE DAY AND INTO THE EVENING. THE STRONGEST WINDS
WILL BE ACROSS NORTHEASTERN WY AND FAR NORTHWESTERN SD...WHERE GUSTS
TO NEAR 45 HTS ARE EXPECTED LATER THIS MORNING AND AFTERNOON.

&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM MDT THIS EVENING
     FOR SDZ001-002-012>014-025-026-031-072-073.

WY...NONE.
&&

$$

SHORT TERM...7
LONG TERM...26
AVIATION...26