000
FXUS63 KBIS 010327
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
927 PM CST SAT FEB 28 2015

.UPDATE...
ISSUED AT 922 PM CST SAT FEB 28 2015

LACK OF CLOUD COVER WEST AND NORTH HAS ALLOWED TEMPS TO FALL BELOW
ZERO SO FAR THIS EVENING AT PLACES LIKE STANLEY AND TIOGA...AND
REACHED AT LEAST ZERO AT HAZEN AND WATFORD CITY. UPSTREAM...CLOUDS
WILL SPREAD INTO THE NORTHWEST BEFORE MIDNIGHT...SO WILL ADJUST
TEMPERATURES DOWN TO ZERO TO 5 BELOW...THEN EXPECT TEMPS TO
REBOUND AFTER MIDNIGHT AS CLOUDS MOVE IN.

UPDATE ISSUED AT 649 PM CST SAT FEB 28 2015

STRATO CU FIELD THAT WAS GOING TO SUPPORT SCATTERED FLURRIES THIS
EVENING HAS RAPIDLY DISSIPATED. SO FOR THIS UPDATE DECREASED
CLOUDS AND REMOVED FLURRIES THROUGH 12Z.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 331 PM CST SAT FEB 28 2015

LOW CLOUDS AND SCATTERED FLURRIES WILL CONTINUE OVER WESTERN NORTH
DAKOTA THROUGH THE REMAINDER OF THE AFTERNOON. THIS ACTIVITY WILL
SLOWLY SPREAD INTO CENTRAL NORTH DAKOTA THIS EVENING.

A VORT LOBE ROTATING AROUND THE BASE OF AN UPPER LEVEL TROUGH AXIS
WILL ENTER NORTHWESTERN NORTH DAKOTA AROUND MIDNIGHT...THEN ROTATE
INTO CENTRAL NORTH DAKOTA AFTER MIDNIGHT. THE UPPER LEVEL ENERGY
SHOULD BE STRONG ENOUGH TO GENERATE LIFT SUFFICIENT FOR ISOLATED
LIGHT SNOW SHOWERS OVER NORTHWESTERN AND NORTH CENTRAL NORTH
DAKOTA...MAINLY AFTER MIDNIGHT. NEW SNOW ACCUMULATIONS SHOULD BE
LIGHT.

BY SUNDAY...THE UPPER LEVEL TROUGH/VORT LOBE IS PROGGED TO EXIT
EAST OF THE REGION. HIGH PRESSURE BUILDING INTO WESTERN NORTH
DAKOTA SHOULD END SNOW CHANCES FROM WEST TO EAST. DECREASING
CLOUDS SHOULD LEAD TO SUNNY SKIES DEVELOPING SUNDAY AFTERNOON.
HOWEVER...TEMPERATURES ARE STILL FORECAST TO BE BELOW NORMAL WITH
READINGS GENERALLY IN THE 20S.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 331 PM CST SAT FEB 28 2015

THE 500MB PATTERN IN THE LONG TERM REMAINS GENERALLY DRY. THE
INITIAL PORTION OF THE LONG TERM WILL BE FOCUSED ON ANOTHER SURGE
OF ARCTIC AIR SHIFTING SOUTHEAST FROM BARROW ALASKA...THROUGH
NORTH DAKOTA...TUESDAY THROUGH WEDNESDAY WITH H85 TEMPS OF -24C TO
-28C. A MODERATING TREND DEVELOPS THURSDAY THROUGH SATURDAY WITH
DRY WEATHER CONTINUING.

FOR SUNDAY NIGHT THROUGH MONDAY...PRIOR TO THE ARCTIC AIR...A
BRIEF PERIOD OF WARM AIR ADVECTION VIA A WEST TO SOUTHWESTERLY
FLOW INTO NORTH DAKOTA WILL RESIDE. THERE IS SOME INDICATION THAT
AN AREA OF LIGHT SNOW OR FLURRIES WILL DEVELOP MONDAY
AFTERNOON/EVENING OVER THE FAR SOUTHERN JAMES RIVER VALLEY AS A
JET STREAK INITIATES OVERHEAD WITH THE NORTHERN AND SOUTHERN
STREAMS BRIEFLY MERGING. THE GFS/NAM GENERATE LIGHT QPF...A COUPLE
HUNDREDTHS...WHILE THE ECMWF/GEM/SREF LEAN MORE TOWARDS FLURRIES
OR NOTHING AT ALL. HAVE MENTIONED FLURRIES FOR NOW AND WILL LET
SUBSEQUENT SHIFTS DECIDE WHETHER TO ADD MEASURABLE POPS IN THE
FUTURE. HIGHS MONDAY WILL RANGE FROM THE 20S NORTH AND EAST TO THE
LOWER 30S SOUTHWEST THROUGH SOUTH CENTRAL.

FOR MONDAY NIGHT THROUGH WEDNESDAY NIGHT...A STRONG ARCTIC FRONT
WILL SWEEP FROM NORTHWEST TO SOUTHEAST MONDAY NIGHT...AHEAD OF THE
STRONG SHORTWAVE TROUGH MENTIONED ABOVE MOVING SOUTHEAST FROM
BARROW ALASKA. PRECIPITATION NOT MUCH OF A CONCERN WITH THIS
SYSTEM OTHER THAN A BRIEF/LIGHT SNOWSHOWERS BEING GENERATED ALONG
AND JUST BEHIND THE FRONT. AS THE SHORTWAVE SHIFTS THROUGH...THE
UPPER FLOW WILL TRANSITION FROM WESTERLY TO A DEEP NORTHERLY FLOW
TUESDAY THROUGH THROUGH WEDNESDAY NIGHT. STRONG COLD AIR ADVECTION
DEVELOPS BEHIND THE FRONTAL PASSAGE AS INDICATED BY THE NAM80 AND
GFS40 6HR PRESSURE RISES OF 10MB...WHICH SLIDES INTO SOUTHWEST
SASKATCHEWAN BY 00Z TUESDAY. THIS WILL THEN TRANSLATE INTO
WILLISTON BY 06Z TUESDAY AND ACROSS BISMARCK AND JAMESTOWN 12Z-18Z
TUESDAY. ISALLOBARIC FORCING WILL GENERATE WINDY CONDITIONS ACROSS
WESTERN AND CENTRAL NORTH DAKOTA WITH THE STRONGEST WINDS FORECAST
OVER JAMES RIVER VALLEY DURING THE DAY TUESDAY. A WIND ADVISORY
MAY BE WARRANTED OVER THE JAMES RIVER VALLEY AS THE LATEST GFS
JAMESTOWN BUFKIT SOUNDING PROFILE SHOWS MIXED LAYER WINDS IN THE
30KT-35KT RANGE WITH NEAR 40KT AT THE TOP. BRISK NORTHWEST WINDS
OF 10 TO 25 MPH WILL CONTINUE THROUGH TUESDAY NIGHT ACROSS ALL OF
WESTERN AND CENTRAL NORTH DAKOTA AS THE SURFACE HIGH REMAINS IN
SOUTHERN ALBERTA AND SASKATCHEWAN. IN TERMS OF TEMPERATURES...THE
CORE OF THE COLDEST AIR IN THE H85-H5 COLUMN WILL BE OVERHEAD
TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING...PER NAEFS
SITUATIONAL AWARENESS TABLE/CLIMATOLOGICAL PERCENTILE. WIND CHILL
VALUES OF 25 BELOW TO 39 BELOW ZERO WILL ENVELOP WESTERN AND
CENTRAL NORTH DAKOTA TUESDAY NIGHT THROUGH WEDNESDAY MORNING.
HIGHS TUESDAY MAINLY IN THE SINGLE DIGITS ABOVE ZERO TO THE LOWER
TEENS IN THE FAR SOUTH AND SOUTHEAST. LOWS TUESDAY NIGHT 5 BELOW
TO 15 BELOW AND HIGHS WEDNESDAY ZERO NORTHEAST TO 13 ABOVE
SOUTHWEST.

THURSDAY THROUGH SATURDAY...WIND CHILL TEMPERATURES TO 30 BELOW ZERO
ARE FORECAST IN THE NORTH CENTRAL AND TURTLE MOUNTAINS...AND
SOUTH TO THE JAMES RIVER VALLEY WEDNESDAY NIGHT THROUGH THURSDAY
MORNING. OTHERWISE...AGREEMENT AMONGST THE GFS AND ECMWF THAT THE
NORTHERLY UPPER FLOW TRANSITIONS TO A NORTHWEST/WESTERLY FLOW
THURSDAY THROUGH SATURDAY. AFTER A BRIEF PERIOD OF WARM ADVECTION
THURSDAY...THE ECMWF SHIFTS A COLD FRONT THROUGH FRIDAY SETTING
THE H85 TEMPS BACK TO SLIGHTLY BELOW ZERO. HOWEVER...THE GFS IS
SLOWER WITH THE COLD FRONT AND SLIDES IT THROUGH ON
SATURDAY...KEEPING FRIDAY IN A WARM AIR ADVECTION REGIME...THEN
COOLING SATURDAY. GENERALLY A DRY PATTERN WITH TEMPERATURES
MODERATING OVERALL. THE SUPERBLEND GIVES HIGHS IN THE 20S
NORTHEAST...TO 30S NORTHWEST THROUGH SOUTHCENTRAL...AND HIGHS IN
THE LOWER 40S SOUTHWEST FRIDAY INTO SATURDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 649 PM CST SAT FEB 28 2015

WEAK COLD FLOW OF COLD AIR WILL BRING SOME STRATO CU FIELDS ACROSS
CENTRAL NORTH DAKOTA AS THEY DISSIPATE THROUGH 06Z. VFR EXPECTED.
A TROUGH OF LOW PRESSURE ACROSS CENTRAL SASKATCHEWAN WILL MOVE
SOUTHEAST INTO NORTH DAKOTA BRINGING ADDITIONAL CLOUDS AND LIGHT
SNOW LATE TONIGHT INTO SUNDAY. LOW VFR TO MVFR LIKELY.


&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...WAA
SHORT TERM...TM
LONG TERM...KS
AVIATION...WAA