000
FXUS63 KBIS 131757
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1257 PM CDT MON MAY 13 2013

.UPDATE...
ISSUED AT 1249 PM CDT MON MAY 13 2013

CLOUDS ARE DIMINISHING RAPIDLY. WINDS HAVE BECOME NORTHWEST AT 20
TO 30 MPH. TEMPERATURES HAVE WARMED INTO THE MID TO UPPER 80S
SOUTH CENTRAL TO THE MID 70S NORTHWEST TO LOWER 80S WEST. ITS
LIKELY A 90 DEGREE HIGH TEMPERATURE SOUTH CENTRAL WILL BE SEEN
THIS AFTERNOON. BISMARCK RECORD OF 92 TODAY WILL BE NEARLY TIED
BUT PROBABLY JUST UNDER AS COOL ADVECTION BEGINNING. CURRENT
FORECAST LOOKS GOOD.

UPDATE ISSUED AT 851 AM CDT MON MAY 13 2013

AT 8 AM CDT...A WARM FRONT EXTENDED FROM LOW PRESSURE IN MANITOBA
THROUGH CENTRAL NORTH DAKOTA. A WEAK COLD FRONT EXTENDED FROM THE
LOW INTO NORTHEAST MONTANA. THE JAMES RIVER VALLEY HAD SOUTHERLY
WINDS WITH SOME GUSTS TO 30 MPH THIS MORNING. WEST WINDS OF 10 TO
20 MPH WERE ACROSS WESTERN NORTH DAKOTA. THE PRECIPITATION AREA
HAS MOVED EAST OF THE REGION.

FOR THE NEXT 6 HOURS...THE WEAK COLD FRONT WILL MOVE THROUGH
WESTERN NORTH DAKOTA PROVIDING INCREASED MIXING TO 800 MB AND
INCREASING WESTERLY WINDS TO 20 TO 30 MPH. HIGHS WILL WILL BE IN
THE 80S TO AROUND 90. THIS WILL RAISE THE FIRE DANGER INTO THE
VERY HIGH CATEGORY AFTER NOON TODAY. RED FLAG WARNING CONTINUES
FOR THIS AFTERNOON AND THIS EVENING. CURRENT FORECAST LOOKS GOOD
OTHER THAN TO ADJUST CLOUD COVER UP ACROSS THE REGION FOR THE
MORNING. SHOULD BE SUNNY THIS AFTERNOON.

UPDATE ISSUED AT 713 AM CDT MON MAY 13 2013

A LOW PRESSURE TROUGH OVER WESTERN NORTH DAKOTA THIS MORNING WILL
MOVE ACROSS THE AREA TODAY...WITH INCREASING WEST TO NORTHWEST
WINDS BEHIND THE TROUGH. CURRENTLY...DENSE CIRRUS SHIELD COVERING
ALL OF WESTERN AND CENTRAL NORTH DAKOTA. WILL BUMP UP SKY COVER
THROUGH THE MORNING HOURS. EXPECT CLOUDS WILL THIN THROUGH THE
AFTERNOON. OTHERWISE NO CHANGES OTHER THAN TO UPDATE LATEST
SURFACE OBSERVATIONS. ALSO NO CHANGES TO CURRENT HEADLINES.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT MON MAY 13 2013

MAIN CONCERN THIS FORECAST PERIOD IS FIRE WEATHER. SEE DISCUSSION
IN FIRE WEATHER SECTION.

A WARM FRONT EXTENDED FROM A LOW IN NORTHERN SASKATCHEWAN TO THE
BORDER OF MONTANA AND NORTH DAKOTA...AND THE WYOMING/SOUTH DAKOTA
BORDER. THIS FRONT IS FORECAST TO MOVE EAST ACROSS THE STATE AND
REACH THE DEVILS LAKE BASIN AND JAMES RIVER VALLEY BY AROUND NOON.
SOUTH WINDS AHEAD OF THE FRONT WILL BECOME WEST/NORTHWEST BEHIND THE
FRONT. THE LOWER ATMOSPHERE IS PROGGED TO MIX OUT TO AROUND
H800...AND SUSTAINED WIND SPEEDS AT THE SURFACE SHOULD INCREASE TO
25 TO 30 MPH. WIND GUSTS TO 35 MPH CAN BE EXPECTED AS WELL.

TONIGHT ANOTHER SYSTEM EMERGES FROM ACROSS THE ROCKIES. A STRONGER
UPPER LEVEL SHORTWAVE WILL BE ASSOCIATED WITH THIS SYSTEM...AND THE
LEADING EDGE OF SHORTWAVE ENERGY REACHES WESTERN NORTH DAKOTA BY
AROUND MID-EVENING...AND SPREADING EAST ACROSS THE STATE BY AROUND
MIDNIGHT. AN ASSOCIATED SURFACE LOW DEVELOPS OVER THE MONTANA/NORTH
DAKOTA BORDER BY MIDNIGHT...AND MOVES EAST/SOUTHEAST ACROSS THE
STATE OVERNIGHT. THE BEST FORCING FOR PRECIPITATION...AND CAPE FOR
THUNDERSTORMS...IS ACROSS THE NORTHERN PART OF THE STATE. A TENTH OF
AN INCH OF PRECIPITATION IS POSSIBLE ACROSS THE NORTHERN TIER OF
COUNTIES...BUT SOME LOCALES MAY SEE 2 TENTHS OF AN INCH OF RAIN.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 410 AM CDT MON MAY 13 2013

THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE FIRE
WEATHER AND WIND HEADLINES ON TUESDAY. ATTENTION THEN TURNS TO THE
LATTER PORTION OF THE PERIOD WITH AN INCREASED RISK OF SHOWER AND
THUNDERSTORMS. SEE THE FIRE WEATHER SECTION FOR MORE DETAILED FIRE
WEATHER DISCUSSION.

ON TUESDAY...A COLD FRONT IS PROGGED TO BE OVER CENTRAL NORTH DAKOTA
AT 12 UTC. NORTHWEST WINDS WILL INCREASE FROM WEST TO EAST THROUGH
THE MORNING...WITH STRONG WINDS ACROSS THE AREA BY EARLY AFTERNOON.
LATEST DETERMINISTIC GUIDANCE SHOWS THAT THE GFS/GEM HAVE COME MORE
IN LINE WITH THE ECMWF...TRACKING A STRONG BUT OPEN WAVE ACROSS
SOUTHERN SASKATCHEWAN AND INTO MANITOBA DURING THE DAY TUESDAY. THE
SUNDAY 00 UTC GFS CLOSED THIS LOW OFF AND WAS TRACKING IT ALONG THE
NORTH DAKOTA BORDER. HOWEVER...WE ARE STILL LOOKING AT A WINDY DAY
ACROSS ALL OF WESTERN AND CENTRAL NORTH DAKOTA ON TUESDAY. BOTH THE
NAM/GFS SHOW A STRONG FALL/RISE COUPLET TRACKING ACROSS SOUTHERN
NORTH DAKOTA...ASSOCIATED WITH THE COLD FRONT WITH 40-50KT WINDS
EXTENDING WELL DOWN INTO THE MIXING LAYER. COUPLET IS NOT AS WELL
DEFINED ACROSS THE NORTH BUT 40-50KT WINDS ALSO EXTEND FAR INTO THE
MIXING LAYER...WITH 00 UTC MONDAY GFS INDICATING 50 KTS TO 875MB AT
KISN AT 18 UTC TUESDAY. WITH THE SURFACE LOW ALSO TRACKING ACROSS
SOUTHERN CANADA...THE STRONGEST GRADIENT WINDS SHOULD LIE ACROSS THE
NORTH. LOOKING AT GFS/NAM BUFR DATA MOMENTUM TRANSFER FROM THE NAM
WOULD INDICATE STRONG WIND ADVISORY CRITERIA. GFS IS A BIT STRONGER
INDICATING A GOOD POSSIBILITY OF HIGH WIND WARNING CRITERIA WINDS.
SEE NO NEED TO MAKE ANY CHANGES TO THE CURRENT WATCH. STILL ENOUGH
TIME FOR THE DAY SHIFT TO TAKE ANOTHER LOOK BEFORE MAKING A DECISION
ON A HIGH WIND WARNING FOR TUESDAY...AND CERTAINLY ENOUGH INDICATORS
TO NOT EVEN THINK ABOUT DROPPING THE HIGH WIND WATCH.

ALTHOUGH MINIMUM RELATIVE HUMIDITIES ARE HIGHER THAN MONDAY ACROSS
THE NORTH...THE VERY STRONG WINDS ARE PUSHING THE FIRE DANGER INDEX
INTO THE EXTREME CATEGORY ACROSS ALL OF WESTERN AND CENTRAL NORTH
DAKOTA...EVEN THE FAR NORTHERN TIER COUNTIES. THEREFORE WILL EXPAND
THE FIRE WEATHER WATCH FOR TUESDAY NORTH TO INCLUDE ALL OF WESTERN
AND CENTRAL NORTH DAKOTA.

WEDNESDAY LOOKS TO BE A QUIET DAY IN THE WAKE OF THE EXITING SYSTEM
WITH A QUASI-ZONAL FLOW OVER THE AREA. TEMPERATURES IN THE 70S AND
LIGHT WINDS WILL SUPPRESS ANY FIRE WEATHER ISSUES.

THURSDAY THROUGH SUNDAY...WITH HIGH LATITUDE BLOCKING DEVELOPING THE
SOUTHERN STEAM FLOW WILL TRACK FROM THE PACIFIC NORTHWEST INTO THE
NORTHERN AND CENTRAL PLAINS...WITH A DEVELOPING UPPER LEVEL LOW
PRESSURE SYSTEM OVER THE NORTHERN PLAINS. THIS WILL BRING AN
INCREASING RISK OF SHOWERS AND THUNDERSTORMS TO THE AREA THURSDAY
THROUGH SUNDAY. THE GFS IS QUICKER TO BRING THE LOW...COMPARED TO
THE ECMWF...BUT BOTH SUGGEST A WETTER REGIME OVER THE AREA WITH
SHOWERS AND THUNDERSTORMS A POSSIBILITY EACH DAY. WITH MODEL
DIFFERENCES...WILL UTILIZE A MODEL BLEND HERE WHICH CURRENTLY BRINGS
SLIGHT CHANCE POPS THURSDAY...AND CHANCE OF GREATER POPS FRIDAY
THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1249 PM CDT MON MAY 13 2013

MAIN HAZARDS TO AVIATION THIS AFTERNOON AND TONIGHT WILL BE
NORTHWEST SURFACE WINDS TO 20 TO 30 KTS. SCATTERED THUNDERSTORMS
ARE POSSIBLE AFTER 7 PM CDT FROM KISN-KMOT. THEN ON TUESDAY...
ANOTHER COLD FRONT WILL BRING STRONG SURFACE WINDS OF 30 TO 45 KTS
ACROSS THE REGION AFTER 15Z KISN-KMOT-KDIK. CONDITIONS SPREADING
SOUTHEAST AFTER 18Z. VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES.

&&

.FIRE WEATHER...
ISSUED AT 410 AM CDT MON MAY 13 2013

FOR TODAY...
UPGRADING THE FIRE WEATHER WATCH TO A RED FLAG WARNING TODAY...AND
ALSO ADDED THE REST OF THE COUNTIES OVER NORTH CENTRAL NORTH
DAKOTA. THE GRAND FORKS NWS ALSO ADDED EASTERN NORTH DAKOTA
COUNTIES IN A RED FLAG AS WELL. THUS ALL COUNTIES IN NORTH DAKOTA
ARE IN A RED FLAG WARNING THIS AFTERNOON INTO EARLY EVENING.

THE LATEST RUN OF MODELS INDICATES STRONG NORTHWEST WINDS OF 25 TO
30 MPH DEVELOPING BEHIND THE WARM FRONT. AS THE LOWER ATMOSPHERE
MIXES UP TO H800...THIS WILL ALLOW SURFACE DEWPOINTS TO DROP AND
RESULTING IN RELATIVE HUMIDITY VALUES THAT WOULD RANGE FROM AROUND
15 PERCENT ACROSS THE SOUTH TO 20 PERCENT NORTH DURING THE AFTERNOON
TO EARLY EVENING HOURS. PASTURES WITH DORMANT GRASSES REMAIN VERY
DRY...EVEN THOUGH THE BEGINNINGS OF GREENUP ARE EVIDENT IN THE WEST.
FIRE DANGER IS FORECAST TO REACH WELL INTO THE VERY HIGH CATEGORY
THIS AFTERNOON.

FOR TUESDAY...
A COLD FRONT WILL MOVE THROUGH THE AREA BRINGING VERY STRONG WEST
TO NORTHWEST WINDS TO ALL OF WESTERN AND CENTRAL NORTH DAKOTA.
SUSTAINED WINDS OF 25 TO 35 MPH WITH GUSTS OVER 45 MPH CAN BE
EXPECTED MOST ANYWHERE ACROSS THE AREA. MINIMUM HUMIDITIES ARE
ONCE AGAIN IN THE TEENS ACROSS THE SOUTHERN PORTION OF THE CWA AND
INCREASE TO 30-35 PERCENT ACROSS THE NORTH. EVEN WITH THE HIGHER
HUMIDITIES ACROSS THE NORTH...THE VERY STRONG WINDS ARE PUSHING
THE FIRE DANGER INDEX INTO THE EXTREME CATEGORY ACROSS ALL BUT THE
FAR NORTHWEST CORNER OF THE CWA. THEREFORE WILL EXPAND THE CURRENT
FIRE WEATHER WATCH FOR TUESDAY NORTH TO INCLUDE THE NORTHERN TIER
COUNTIES.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM CDT /7 PM MDT/ THIS EVENING FOR
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.

FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR NDZ001>005-009>013-017>023-025-031>037-040>048-050-
051.

HIGH WIND WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
NDZ003-004-011-012-019>022-034-035-042-045-046.

HIGH WIND WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
NDZ001-002-009-010-017-018-031>033-040-041-043-044.

HIGH WIND WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING
FOR NDZ005-013-023-025-036-037-047.

&&

$$

UPDATE...WAA
SHORT TERM...JV
LONG TERM...TWH
AVIATION...WAA
FIRE WEATHER...JV/TWH