Area Forecast Discussion
Issued by NWS Grand Forks, ND

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000
FXUS63 KFGF 211151
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
651 AM CDT MON JUL 21 2014

.UPDATE...
ISSUED AT 651 AM CDT MON JUL 21 2014

WEAK 850MB BOUNDARY RESPONSIBLE FOR ISOLD THUNDERSTORMS ACROSS THE
FAR SOUTHERN FA. AS WARMER MID-LEVEL TEMPS BUILD INTO THE REGION
THESE STORMS SHOULD DISSIPATE IN THE NEXT COUPLE HOURS. THE SAME
APPLIES TO THE ACTIVITY NEAR THE INTERNATIONAL BORDER.

INCOMING MODEL GUIDANCE HAS NOT CHANGED THE EXPECTED WEATHER FOR
THIS AFTERNOON AND EVENING.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 400 AM CDT MON JUL 21 2014

THE MAIN CONCERN WILL BE THE MODERATE RISK OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. THE OTHER CONCERN WILL
BE HEAT INDICES THIS AFTERNOON. 00Z MODELS IN DECENT
AGREEMENT...WITH ONLY MINOR DIFFERENCES CONCERNING HOW FAR NORTH
THE WARM FRONT WILL BE LOCATED...AND TIMING OF STORMS. THE SPC
MODERATE RISK HAS BEEN SHIFTED NORTHWARD BECAUSE THERE HAS BEEN A
NORTHWARD TREND IN THE GUIDANCE WITH THE WARM FRONT/SFC LOW TRACK.

WATER VAPOR IMAGERY INDICATES A COUPLE SHORTWAVES THAT WILL
INFLUENCE THE SITUATION TODAY. THE FIRST IS OVER OREGON...AND
WILL PROPAGATE ACROSS SOUTHERN CANADA. THE SECOND WILL EJECT FROM
NEVADA AND PROPAGATE THROUGH THE FA TODAY/THIS EVENING. AHEAD OF
THESE SHORTWAVES...STRONG INSTABILITY WILL SET UP ALONG AND SOUTH
OF A WARM FRONT. THIS WARM FRONT WILL LIKELY BE LOCATED NEAR
HIGHWAY 2 BY MID-AFTERNOON. MOST GUIDANCE CONTINUES TO SUGGEST
THAT A THUNDERSTORM COMPLEX WILL INITIATE ACROSS CENTRAL NORTH
DAKOTA...AND MOVE SOMEWHERE INTO THE SOUTHERN 2/3RDS OF THE FA
THIS EVENING. ADJUSTED THE TIMING OF POPS/WX TO THE LATEST
AVAILABLE CAM GUIDANCE...AND KEPT THE SEVERE/HEAVY RAIN MENTION
ACROSS MOST AREAS. WITH SUCH STRONG INSTABILITY...ALL MODES OF
SEVERE WEATHER WILL BE POSSIBLE...WITH THE DAMAGING WIND THREAT
INCREASING THROUGH THE EVENING AS THE SYSTEM MATURES AND A 50+
KNOT 500MB JET ENTERS THE REGION. WILL CONTINUE TO MONITOR THE
INCOMING CAM GUIDANCE AND ATTEMPT TO ADD FURTHER DETAILS WITH
FUTURE UPDATES CONCERNING THIS HIGHER END SEVERE THREAT.

THE CURRENT HEAT ADVISORY LOOKS GOOD AND WILL MAKE NO
CHANGES...ALTHOUGH AREAL EXPANSION TO THE NORTH MAY NEED TO BE
CONSIDERED.

ALSO...CONTINUED TO MENTION HEAVY RAIN IN THE FORECAST WITH PWATS
APPROACHING 2 INCHES WHERE THE STORMS ARE EXPECTED. THIS SYSTEM
SHOULD BE FAIRLY PROGRESSIVE AS IT MOVES THROUGH THE
REGION...NEGATING THE NEED FOR A FLASH FLOOD WATCH. HOWEVER...IT
SHOULD BE NOTED THAT ISOLATED VERY HEAVY RAIN WILL OCCUR AND FLASH
FLOOD WARNINGS ARE STILL VERY POSSIBLE...JUST NOT WIDESPREAD IN
COVERAGE.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 400 AM CDT MON JUL 21 2014

TUESDAY-WEDNESDAY NIGHT...UPPER RIDING WILL BUILD ACROSS THE
ROCKY MOUNTAINS PLACING THE FA UNDER THE INFLUENCE OF HIGH
PRESSURE. THIS WILL LEAD TO MOSTLY DRY WEATHER AND TEMPERATURES
NEAR OR SLIGHTLY BELOW NORMAL VALUES.

THURSDAY-SUNDAY...MEDIUM-RANGE MODELS ARE IN GOOD AGREEMENT
SHOWING AN EASTERN PACIFIC WAVE RIDING OVER AND FLATTENING THE
SHORT-WAVE RIDGE ACROSS THE NORTHERN PLAINS. AS A RESULT...A SLOW
MOVING MID-LEVEL TROUGH WILL MOVE ACROSS THE FORECAST AREA WITH
THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS THURSDAY NIGHT
THROUGH FRIDAY. INSTABILITY NOT ALL TOO GREAT...SO NOT EXPECTING
WIDESPREAD SEVERE WEATHER AT THIS TIME. WILL FOLLOW ALL BLEND POPS
FOR COORDINATION WITH SURROUNDING WFOS...BUT POPS LIKELY OVERDONE
FOR THE WEEKEND. TEMPERATURES THROUGH THE PERIODS WILL BE MUCH
CLOSER TO SEASONAL NORMALS WITH HIGHS IN THE MID 70S TO LOWER 80S
AND LOWS IN THE MID 50S TO LOWER 60S.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 651 AM CDT MON JUL 21 2014

VFR CONDITIONS THROUGH MUCH OF THE DAY. THUNDERSTORMS BECOME
LIKELY LATER THIS AFTERNOON INTO THE EVENING HOURS...AND INCLUDED
WITH THIS TAF ISSUANCE. THE POTENTIAL EXISTS FOR STRONG TO SEVERE
STORMS...BUT CONFIDENCE IN EXACT LOCATION NOT ENOUGH TO INCLUDE
WITH THIS TAF ISSUANCE.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
     FOR NDZ039-049-052-053.

MN...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
     FOR MNZ003-029>032-040.

&&

$$

UPDATE...TG
SHORT TERM...TG
LONG TERM...TG/ROGERS
AVIATION...TG






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