FXUS63 KBIS 140837
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
337 AM CDT SUN MAR 14 2010
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT...
LATEST WATER VAPOR IMAGERY SHOWS A WEAK LOW CIRCULATION ALONG THE
CENTRAL NORTH/SOUTH DAKOTA BORDER. THIS HAS BEEN WELL ADVERTISED BY
THE ECMWF WHICH STILL CONTINUES TO DEVELOP LIGHT PRECIPITATION OVER
OUR SOUTHEASTERN ZONES TODAY AND TONIGHT. CONCUR WITH THIS IDEA AND
IT HAS SOME SUPPORT FROM THE GFS AS WELL. THE LATEST FOG/STRATUS
LOOP CONTINUES TO SHOW STRATUS COVERING THE ENTIRE CWA. NAM/GFS
925MB MOISTURE/RH FIELDS KEEP THIS IN PLACE THROUGH MONDAY...THEN
BEGINS TO THIN IT OUT MONDAY NIGHT ACROSS THE NORTH AND OVER THE
SOUTHERN ZONES DURING THE DAY TUESDAY. HENCE EXPECT HIGHS TODAY AND
MONDAY SIMILAR TO WHAT OCCURRED SATURDAY...HIGHS 35F TO 40F.
OVERNIGHT LOWS TONIGHT WILL AGAIN BE SIMILAR TO THIS MORNINGS LOWS
WITH TEMPERATURES BETWEEN 30F AND 35F AS EXTENSIVE CLOUDS AND FOG
CONTINUE. LATEST REGIONAL RADAR IS SHOWING SOME LIGHT ECHOES OVER
EASTERN NORTH/SOUTH DAKOTA BEGINNING TO ADVECT WEST AND NORTHWEST.
WITH ENOUGH UPWARD LIFT TODAY IN OUR SOUTHEAST ZONES WILL MENTION
SOME RAIN SHOWERS THERE. OUT WEST...A SHORTWAVE TROUGH NOW ADVANCING
THROUGH EASTERN ALBERTA WILL BRING A RISK FOR LIGHT FREEZING
RAIN/AND OR RAIN SHOWERS THIS MORNING...THEN A SLIGHT CHANCE OF RAIN
SHOWERS THIS AFTERNOON. IN BETWEEN ACROSS NORTH CENTRAL AND SOUTH
CENTRAL NORTH DAKOTA EXPECT DRY CONDITIONS TODAY BUT CLOUDS AND
AREAS OF FOG WILL CONTINUE. AS THIS SHORTWAVE TROUGH ALOFT SLIDES
EAST TONIGHT...THERE WILL BE A SLIGHT CHANCE OF DRIZZLE OR LIGHT
FREEZING DRIZZLE PER NAM/GFS BUFR SOUNDINGS ACROSS MOST OF THE CWA.
BEGINNING MONDAY A HIGHLY AMPLIFIED RIDGE WILL BEGIN TO NUDGE CLOSER
TO NORTH DAKOTA FROM THE INTER MOUNTAIN WEST. THIS RIDGE WILL BRING
WARMER TEMPERATURES FOR TUESDAY AFTERNOON AS THE BOUNDARY LAYER
SHOWS SIGNS OF DRYING AND TEMPERATURES RISE INTO THE UPPER 30S TO
MID 40S ACROSS THE CWA.
WILL CANCEL THE DENSE FOG ADVISORY FOR ALL OF THE CWA EXCEPT IN THE
FAR NORTHEAST AND EAST WHERE SURFACE HIGH PRESSURE RESIDES AND THE
DENSE FOG REMAINS TRAPPED.
.LONG TERM...WEDNESDAY THROUGH SATURDAY...
MAIN PROBLEM IN THE DAY 4-5 PERIOD WILL BE TEMPERATURES AND SLIGHT
PRECIPITATION CHANCES. AN UPPER LEVEL RIDGE WILL TRAVERSE THE AREA
ON WEDNESDAY...WHILE BEING FLATTENED BY PACIFIC ENERGY. UPSTREAM
RIDGING WILL ALLOW FOR AN UPPER LEVEL TROUGH TO DEVELOP OVER THE
CENTRAL PORTION OF THE COUNTRY. THIS WILL BRING COOLER TEMPERATURES
AND INCREASED PRECIPITATION CHANCES. AT THIS TIME IT APPEARS THE
INITIAL SHORTWAVE ENERGY BE MOVING INTO A RATHER DRY ATMOSPHERE.
MODELS INDICATE THE NEXT SHORTWAVE DROPPING FARTHER SOUTH AS IT
MOVES ACROSS THE NORTHERN ROCKIES...AND BEST DYNAMICS WILL BE SOUTH
AND WEST OF THE LOCAL AREA...EXCEPT FOR POSSIBLY THE SOUTHWEST.
WILL CONTINUE WITH PREVIOUS POPS...WHICH ARE SLIGHT CHANCE POPS OVER
THE SOUTHWEST HALF OF THE CWA ON THURSDAY...AND IN THE WEST THURSDAY
NIGHT. PREVIOUS TEMPERATURES ALSO LOOK GOOD WITH MAINLY 40S...EXCEPT
LOWER 50S SOUTHWEST ON WEDNESDAY. ON THURSDAY...EXPECT MAINLY 40S
BUT IT WILL BE COOLER NORTH AND WEST...AND ABOUT THE SAME OR PERHAPS
A COUPLE DEGREES WARMER IN THE SOUTHEAST.
LATE IN THE EXTENDED PERIOD...AT THIS TIME IT APPEARS A NORTHWEST
FLOW WILL BE THE RULE WITH SIGNIFICANTLY COOLER TEMPERATURES OVER
THE WEEKEND...ALTHOUGH THE ECMWF IS NOT AS IMPRESSIVE WITH THE COOL
DOWN. WILL LIKELY SEE A FEW IMPULSES MOVING THROUGH THE FLOW WHICH
COULD GENERATE SOME LIGHT PRECIPITATION...BUT THIS PATTERN WOULD
SUGGEST A LOW PROBABILITY FOR A MAJOR PRECIPITATION MAKER OVER THE
LOCAL AREA THROUGH THE WEEKEND. HOWEVER...WILL NEED TO MONITOR FOR
ANY CHANGES TO THE CURRENT STORM TRACK WHICH COULD INCREASE OUR
PRECIPITATION CHANCES.
&&
.AVIATION...
WEAK HIGH PRESSURE WILL REMAIN OVER THE AREA TODAY WITH WIDESPREAD
MVFR-IFR CIGS AND LIGHT AND VARIABLE WINDS. VISIBILITIES EARLY THIS
MORNING HAVE BEEN IMPROVING AND ARE MAINLY MVFR...EXCEPT FOR EASTERN
PORTIONS OF THE CWA. COULD SEE A TEMPORARY DROP IN VISIBILITIES
AROUND SUNRISE...BUT THE MAIN IMPACT TODAY WILL BE LOW CEILINGS.
LATER TODAY AND TONIGHT...STRONGER HIGH PRESSURE BUILDS OVER THE
AREA FROM THE NORTHWEST AND THIS WILL TURN THE SURFACE FLOW NORTH TO
NORTHWEST ACROSS THE CWA. HOWEVER...THIS IS NOT EXPECTED TO BRING
ANY SIGNIFICANT IMPROVEMENT TO THE LOW CEILINGS. WILL CONTINUE WITH
MAINLY IFR CEILINGS TONIGHT AND A RETURN OF AREAS OF FOG CAN ALSO BE
EXPECTED.
&&
.HYDROLOGY...
AS OF EARLY SUNDAY MORNING...RIVER LEVELS CONTINUE TO RISE ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. MANY WATERSHEDS HAD STANDING WATER
STARTING TO MOVE TOWARDS SMALL STREAMS AND RIVERS. THESE INCLUDE
APPLE CREEK NEAR MENOKEN...BEAVER CREEK NEAR LINTON...THE CANNONBALL
NEAR BREIEN...THE LITTLE MISSOURI NEAR MARMARTH....THE JAMES AND
KNIFE RIVERS AND PIPESTEM CREEK AREAS.
BEAVER CREEK AT LINTON SURPASSED ACTION STAGE OF 7.0 FEET ON
SATURDAY EVENING AS HAS SHOWN A CONTINUED SLOW RISE INTO EARLY
SUNDAY MORNING. RISES ARE ALSO NOTED AT THE UPSTREAM GAGE ON BEAVER
CREEK NORTH OF STRASBURG. THIS GAGE WILL HAVE TO BE MONITORED FOR
CONTINUED RISES. A HYDROLOGIC STATEMENT...RVS...HAS BEEN ISSUED FOR
LINTON PER COORDINATION WITH THE MBRFC SATURDAY EVENING.
THE TEMPERATURE FORECAST FOR SUNDAY AND MONDAY CALLS FOR HIGH
TEMPERATURES ACROSS WESTERN AND CENTRAL NORTH DAKOTA GENERALLY
BETWEEN 35 AND 40 WITH OVERNIGHT LOW TEMPERATURES IN THE UPPER 20S.
WITH LOW CLOUDS AND FOG PREVENTING MUCH WARMING...A CONTINUED SLOW
MELT IS EXPECTED.
HOWEVER...A WARM UP IS FORECAST TUESDAY THROUGH THURSDAY ACROSS THE
AREA....WITH HIGH TEMPERATURES GENERALLY BETWEEN 45 AND 50...
AND POTENTIALLY IN THE LOWER 50S IN THE SOUTHWEST. OVERNIGHT LOW
TEMPERATURES NEAR TO SLIGHTLY ABOVE FREEZING MAY ALSO BE
POSSIBLE...FURTHER ACCELERATING SNOWMELT AND RUNOFF...AND
HEIGHTENING OVERLAND AND RIVER FLOODING CONCERNS.
FORECAST MODELS CONTINUE TO SHOW A POSSIBLE STORM SYSTEM FOR THE
MIDWEST AROUND MARCH 19 AND 20. ALTHOUGH THE TREND HAS BEEN TO TAKE
THE SYSTEM SOUTH OF NORTH DAKOTA...IT IS STILL VERY EARLY...AND THIS
SYSTEM WILL HAVE TO BE MONITORED FOR ANY CHANGE IN TRACK.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR NDZ004-005-
012-013-022-023-025-037.
&&
$$
KS/TWH/PJA
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