Area Forecast Discussion
Issued by NWS Bismarck, ND

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KBIS 310251
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
951 PM CDT THU OCT 30 2014

.UPDATE...
ISSUED AT 944 PM CDT THU OCT 30 2014

COOL AND DRY AIR MOVING INTO THE CENTRAL AND EAST THIS EVENING.
LOWERED MINS ABOUT 3 DEGREES NORTH CENTRAL AND NORTHEAST. CLOUDS
WILL NOW OCCUPY ONLY THE SOUTHWEST AND WEST CENTRAL. WILL KEEP
MENTION OF FZDZ AFTER MIDNIGHT SOUTHWEST BUT SHOULD ONLY BE
PATCHY.

UPDATE ISSUED AT 621 PM CDT THU OCT 30 2014

LARGE SURFACE HIGH PRESSURE ACROSS MANITOBA WILL MOVE SOUTH
TONIGHT. THE HIGH WILL BRING CLEARING SKIES TO CENTRAL NORTH
DAKOTA THIS EVENING AND EVENTUALLY THE WEST AFTER SUNRISE FRIDAY.
AFTER MIDNIGHT AGREE THERE IS AT LEAST A SLIGHT CHANCE FOR -FZDZ
OVER THE SOUTHWEST DUE TO WEAK UP SLOPE FLOW SUPPORTING LOW LEVEL
SUPER SATURATION ABOVE -10C WITH DRY AIR ABOVE. CURRENT FORECAST
LOOKS GOOD.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 404 PM CDT THU OCT 30 2014

LOW LEVEL STRATUS AND FREEZING DRIZZLE POTENTIAL TONIGHT...AND
STRONG WINDS FRIDAY HIGHLIGHT THE SHORT TERM.

VISIBLE SATELLITE THROUGH 2015 UTC SHOWS THAT THE STRATUS HAS
ERODED ACROSS THE TURTLE MOUNTAINS...AND DEVILS LAKE BASIN INTO
THE UPPER JAMES RIVER VALLEY. THIS IS GENERALLY ON TRACK...IF NOT
JUST A BIT SLOWER WHEN COMPARED TO THE LOW LEVEL RH FIELDS ON THE
17 THROUGH 19 UTC RAP AND HRRR ITERATIONS. STRATUS EROSION WILL
CONTINUE THROUGH THE AFTERNOON AND EARLY EVENING AS LOW LEVEL
SUBSIDENCE INCREASES WITH THE BUILDING SURFACE HIGH. THERE ARE SOME
INDICATIONS IN THE RAP/HRRR AND OBSERVED SATELLITE TRENDS THAT THE
STRATUS MAY LINER ALONG AND WEST OF HIGHWAY 85 THROUGH MUCH OF THE
NIGHT. THUS...WITH SUNDOWN STRATUS BUILD DOWN IS
POSSIBLE...LEADING TO FOG AND POTENTIALLY PATCHY FREEZING DRIZZLE
WITH SATURATION WARMER THAN -10C ACROSS THE SOUTHWEST.
OTHERWISE...A COLD NIGHT IS EXPECTED FOR STRATUS FREE AREAS WITH
LIGHT WINDS AND CLEAR SKIES IN THE SURFACE HIGH AND LOWS IN THE
TEENS.

FOR FRIDAY...ISSUED A WIND ADVISORY FOR THE SOUTHWEST FROM 18-00
UTC. STRONG SOUTHEASTERLY WIND ARE FORECAST AS THE PRESSURE
GRADIENT INCREASES BETWEEN THE DEPARTING SURFACE HIGH PROPAGATING
INTO THE UPPER MISSISSIPPI VALLEY AND THE STATIONARY LEE FRONT
ACROSS MONTANA AND WYOMING. 0.5 KM WINDS INCREASE TO 50 KTS BY 00
UTC ACROSS MUCH OF THE WESTERN AND CENTRAL NORTH DAKOTA.
HOWEVER...MIXING HEIGHTS ARE RATHER SHALLOW GIVEN THE LOW LEVEL
WARM AIR ADVECTION INDUCED INVERSION. THUS...THE HIGHER TERRAIN OF
THE SOUTHWEST HAS THE BEST CHANCE OF TAPING INTO THE STRONG WINDS
AT THE BASE OF THE INVERSION. SHOULD MIXING HEIGHTS BE GREATER
THAN FORECAST...AN EXPANSION IN TIME AND AREA OF THE ADVISORY MAY
BE POSSIBLE.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 404 PM CDT THU OCT 30 2014

MAIN IMPACTS IN THE EXTENDED...WINDY CONDITIONS FRIDAY
EVENING...RAIN/SNOW MONDAY.

VERY WINDY CONDITIONS ARE FORECAST TO
DEVELOP OVER SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON. WARM AIR
ADVECTION...COMBINED WITH LARGE PRESSURE FALLS AHEAD OF A LOW
PRESSURE CENTER IN EASTERN MONTANA...WILL BRING IN GUSTY WINDS
AROUND 40 MPH. WINDS SHOULD DIMINISH BY SATURDAY AS THE PRESSURE
GRADIENT WEAKENS ACROSS NORTH DAKOTA.

THE LATEST GUIDANCE (12 UTC GFS/ECMWF/SREF/NAM) ARE IN GOOD
AGREEMENT IN THE TIME AND PLACEMENT OF THE SUNDAY/MONDAY SHORTWAVE
TROUGH. THE BULK OF THE PRECIPITATION SHOULD REMAIN WEST OF NORTH
DAKOTA SUNDAY. AS THE SHORTWAVE ENTERS SASKATCHEWAN AND MANITOBA
SUNDAY NIGHT INTO MONDAY...WRAP AROUND MOISTURE COULD BRING IN A
CHANCE OF RAIN OR SNOW ACROSS THE NORTH MONDAY MORNING.

ANOTHER SHORTWAVE IS FORECAST TO SWING OUT OF SASKATCHEWAN AND
ENTER NORTH DAKOTA TUESDAY NIGHT/WEDNESDAY MORNING. THE ECMWF IS A
BIT FURTHER NORTH WITH PRECIPITATION THAN THE GFS. IF THE TRACK ON
THE ECMWF HOLDS TRUE THEN VERY LITTLE IF ANY PRECIPITATION WILL
IMPACT NORTH DAKOTA WITH THIS PARTICULAR SHORTWAVE TROUGH. THE
ECMWF IS ALSO WARMER THAN THE GFS...POINTING TO ALL RAIN PRECIP
RATHER THAN THE RAIN/SNOW MIX OF THE GFS. RIGHT NOW ONLY A SLIGHT
CHANCE FOR PRECIPITATION WAS ADDED TO THE FORECAST.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 944 PM CDT THU OCT 30 2014

LARGE SURFACE HIGH PRESSURE MOVING SOUTH INTO THE CENTRAL AND
EASTERN DAKOTAS TONIGHT. THIS WILL PUSH THE BAND OF STRATUS CLOUDS
WESTWARD TO OCCUPY THE SOUTHWEST WHERE UP SLOPE FLOW SHOULD
CONTRIBUTE TO SOME PATCHY FREEZING DRIZZLE ISSUES TONIGHT. AT THIS
TIME STILL TOO UNCERTAIN TO INCLUDE IN TAF FOR KDIK BUT IFR WILL
PERSIST THROUGH MOST IF THE NIGHT WITH VFR CONDITIONS AFTER
SUNRISE FRIDAY. ELSEWHERE VFR.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TO 6 PM MDT FRIDAY FOR NDZ031>033-040-
041-043-044.

&&

$$

UPDATE...WAA
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...WAA






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.