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000
FXUS63 KBIS 191009
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
509 AM CDT SUN MAY 19 2013

.SHORT TERM...(TODAY AND TONIGHT)

ISSUED AT 500 AM CDT SUN MAY 19 2013

FORECAST HIGHLIGHT/CONCERN IN THE SHORT TERM PERIOD WILL BE
RAINFALL AMOUNTS THROUGH TONIGHT.

CURRENTLY...LONG WAVE TROUGH OVER THE WESTERN AND CENTRAL UNITED
STATES. STRONG EMBEDDED S/WV IMPULSE LIFTING NORTH ACROSS WESTERN
SOUTH DAKOTA...VISIBLE ON REGIONAL RADAR AND SATELLITE IMAGERY
WITH CYCLONIC CIRCULATION SITUATED BETWEEN THE BLACK HILLS AND
PIERRE. ASSOCIATED SURFACE TROUGH OVER CENTRAL SOUTH DAKOTA WITH
WRAP AROUND SHOWERS AND STORMS LIFTING NORTH ACROSS SOUTH CENTRAL
AND EASTERN NORTH DAKOTA.

THE LATEST 00Z GFS AND 00Z ECMWF HAVE TRENDED TOWARDS MORE OF A
CONSENSUS FOR THE NEXT 24 HOURS...WITH WIDESPREAD PRECIPITATION
DEVELOPING ACROSS WEST AND CENTRAL NORTH DAKOTA TODAY AND TONIGHT
AND BEYOND AS THE STRONG S/WV IMPULSE NOW OVER WESTERN SOUTH
DAKOTA CLOSES OFF AND REMAINS QUASI-STATIONARY OVER SOUTH
DAKOTA/NORTHERN NEBRASKA THROUGH TONIGHT. MOISTURE WILL CONTINUE
TO WRAP BACK EAST/FEED INTO THE LOW PROVIDING ADDITIONAL RAINFALL
UP TO TWO INCHES...LOCALLY HIGHER...FROM THIS MORNING THROUGH 12Z
MONDAY ACROSS THE SOUTHERN TWO THIRDS OF THE CWA.

WITH ANOTHER INCH OR TWO POSSIBLE MONDAY AND MONDAY NIGHT
(POSSIBLE MORE NORTH)...WE OPTED TO ISSUE A FLOOD WATCH FOR ALL
OF WEST AND CENTRAL NORTH DAKOTA WITH ALREADY 1-2 INCHES OF RAIN
MEASURED SOUTHWEST...SOUTH CENTRAL...AND SOUTHEAST FROM THE PAST
24-48 HOURS...OR FROM BOWMAN TO BISMARCK AND JAMESTOWN. WHILE ALL
BUT THE NORTHWEST AND FAR NORTH CENTRAL IS IN THE WPC DAY 1 (06Z
SUNDAY THROUGH 12Z MONDAY) SLIGHT RISK OF RAINFALL EXCEEDING FLASH
FLOOD GUIDANCE...THE MOST PRONE AREA IS ACROSS MY SOUTHEAST WHERE
LINGERING INSTABILITY WILL BE TODAY AND TONIGHT...AND WHERE HEAVY
RAIN FELL SATURDAY EVENING WITH THE STRONG TO SEVERE STORMS THAT
MOVED THROUGH PARTS OF THE JAMES RIVER BASIN. CONVECTIVE
POTENTIAL DECREASES ELSEWHERE AS WE HEAD INTO MONDAY...BUT STILL
ANTICIPATE HEAVY RAINFALL WITH VERY STRONG FORCING EXPECTED. WITH
MODELS FLUCTUATING THE PAST COUPLE OF DAYS...FELT IT TO BE SAFER
TO INCLUDE THE ENTIRE AREA IN THE WATCH IN CASE OF FURTHER
POSITION CHANGES OF THE UPPER LOW.


.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 500 AM CDT SUN MAY 19 2013

THE MAIN FORECAST ISSUE THROUGH THE LONG TERM PERIOD IS CONTINUED
HEAVY RAIN AND POTENTIAL FOR FLOODING. THE LATEST SUITE OF 19/00Z
MODELS IS COMING INTO BETTER AGREEMENT REGARDING THE TRACK OF THE
CLOSED UPPER LOW THROUGH THE REGION. THE CONSENSUS INDICATES A
PROLONGED PERIOD OF MODERATE TO HEAVY RAIN CONTINUING MONDAY INTO
TUESDAY...IMPACTING MOST IF NOT ALL OF WESTERN AND CENTRAL NORTH
DAKOTA. ADDITIONAL RAINFALL AMOUNTS UP TO 4 INCHES ARE EXPECTED. IN
ADDITION TO FLOODING CONCERNS ALONG SMALL STREAMS...AND LOW LYING
AREAS...WILL BE MONITORING RIVERS CLOSELY THIS WEEK...ESPECIALLY THE
FASTER RESPONDING POINTS SUCH AS APPLE CREEK NEAR MENOKEN. SHOWERS
ARE EXPECTED TO BECOME MORE SCATTERED TUESDAY NIGHT INTO WEDNESDAY.
ALTHOUGH SOME THUNDERSTORMS WILL BE POSSIBLE MONDAY INTO
TUESDAY...NO SEVERE WEATHER IS EXPECTED. THE NEXT BEST CHANCE OF
RAIN WILL BE LATE FRIDAY INTO SATURDAY. EXPECT COOL TEMPS THROUGH
TUESDAY...WITH A GRADUAL WARMING TREND INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 500 AM CDT SUN MAY 19 2013

IFR AND LOWER STRATUS AND AREAS OF FOG WILL DEVELOP OVER ALL
TERMINALS EARLY THIS MORNING AND PERSIST THROUGH AT LEAST 14-15Z.
KISN-KMOT LOOK TO SCATTER OUT TO MVFR LATER SUNDAY MORNING...WHILE
THE SOUTH MAINTAINS LOW CIGS NEAR IFR. MODERATE TO HEAVY BANDS OF
RAIN AND ISOLATED THUNDERSTORMS ALSO EXPECTED SUNDAY AND SUNDAY
NIGHT MOST AREAS.


&&

.BIS WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH TUESDAY MORNING FOR NDZ001>005-009>013-
017>023-025-031>037-040>048-050-051.

&&

$$

SHORT TERM/AVIATION...NH
LONG TERM...RP KINNEY