Area Forecast Discussion
Issued by NWS Grand Forks, 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 KFGF 122350
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
650 PM CDT SAT JUL 12 2014

.UPDATE...
ISSUED AT 650 PM CDT SAT JUL 12 2014

ADJUSTED POPS FOR LINE OF STORMS MOVING THROUGH THE NORTHERN
COUNTIES. MESOSCALE MODELS PERSIST IN EVENTUALLY BREAKING UP THE
LINE AS IT MOVES SOUTH...A LITTLE LESS SO IN OUR EASTERN COUNTIES.
GIVEN THE WEAKENING INSTABILITY FURTHER SOUTH THIS SEEMS
REASONABLE. KEPT POPS DECREASING THROUGH THIS EVENING BEFORE
EVENTUALLY ENDING AFTER MIDNIGHT. RAIN COOLED AIR HAS ALREADY
DROPPED TEMPS INTO THE 50S ALONG THE NORTHERN TIER...SO LOWERED
TEMPS FOR THE REST OF THE EVENING BUT KEPT LOWS AROUND 50 FOR NOW.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 310 PM CDT SAT JUL 12 2014

IN THE VERY NEAR TERM THE MAIN FOCUS IS THE SLIGHT RISK OF SEVERE
WEATHER EARLY THIS EVENING. WV SHOWS STRONG DRY PUNCH...SUGGESTIVE
OF JET DEPICTED IN MODELS...PUNCHING RAPIDLY SOUTH. VARIOUS HIGH
RES MODELS SHOW A FAST MOVING LINE OF TSRA ALONG COLD FRONT. MARGINAL
INSTABILITY...0 - 1KM CAPE TO 700 J/KG AND SWI -2C BUT 0 - 6KM
BULK SHEAR CLIMBS TO 60KTS AT 00Z...YET IS POST FRONTAL. BASED ON
THE ATMOSPHERIC PROFILE SUSPECT MAIN THREAT IS DAMAGING WINDS. 15Z
SREF 3HR SVR TSTM PROB SUPPORTS +TSRA 21Z - 03Z.

FRONTAL BOUNDARY ZIPS THROUGH CWFA OVERNIGHT. WINDS SHOULD
DIMINISH AFTER INITIAL PUSH WITH CONVECTION AND LOW LEVEL CAA IS
SPENT. FROM A BOUNDARY LAYER STANDPOINT THE AIRMASS IS ONLY
SLIGHTLY COOLER 12Z SUNDAY THAN 12Z THIS MORNING. SO EXPECT MIN
TEMPS A FEW DEGREES LOWER THAN SATURDAY. STRONGER LOW LEVEL CAA
DEVELOPS DURING THE DAY SO TEMPERATURES WILL BE SLOW TO
RECOVER....HIGHS PERHAPS 10F COOLER. WINDS INCREASE AS WELL WITH
DIRECTION FAVORING A MORE EFFECTIVE MIXING PROFILE. VARIOUS
GUIDANCE SUGGEST A WINDY DAY...PERHAPS CLOSE TO WIND ADV CRITERIA
BY SUNDAY AFTERNOON.

WINDS DIMINISH SUNDAY NIGHT BUT SUSTAINED LOW LEVEL CAA
...ISALLOBARIC COMPONENT AND 30+KTS AT 850 SUGGEST ONLY MODEST
DECREASE.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 310 PM CDT SAT JUL 12 2014

DEEP UPPER LOW HAS BEEN CONSISTENTLY FORECAST TO DROP FROM SOUTHWEST
ONTARIO INTO THE WESTERN GREAT LAKES MONDAY. BEST CHANCE FOR
SHOWERS SHOULD BE CLOSER TO THE DEEP CIRCULATION. WITH COLDER AIR
ALOFT -RASH POSSIBLE WEST OF RRV AS WELL. LACK OF SIGNIFICANT
INSTABILITY WILL NOT INTRODUCE THUNDER...BUT ISOLD -TSRA PSBL DUE
TO STRENGTH OF 700 COLD POOL.

VARIOUS MODELS HAVE CONTINUED TO COME CLOSER TOGETHER PAINTING MONDAY
AS A CHILLY MID JULY DAY. DYNAMIC MODELS TEND TO BE WARMER WHILE THE
MOS/BC/WEIGHTED MODELS COOLER. LOCAL VERIFICATION SUGGESTS THE
DYNAMIC MODELS HAVE BEEN TOO WARM SO WILL LEAN TOWARDS THE
WEIGHTED MOS/BC VERSIONS. LATEST FORECASTS STILL PRESENT
POSSIBILITY OF RECORD OR NEAR RECORD LOW MAXIMUM TEMPERATURES
MONDAY.

QUITE WEATHER FOR TUESDAY AS HIGH SETTLES IN AND GRADIENT RELAXES.
LOW LEVEL THERMAL PROFILE SUGGESTS 2C TO 4C WARMING AND SHOULD BE A
FAIR AMOUNT OF SOLAR...YET LACK OF MIXING KEEPS TEMPERATURE BELOW
MEDIAN.

SURFACE HIGH PRESSURE AND NORTHWEST FLOW ALOFT (WITHOUT MUCH
EVIDENCE OF ANY SHORT WAVE ACTION) SHOULD MEAN MAINLY SUNNY DRY
WEATHER FOR THE WED/THUR TIME FRAME COMING OUT OF OUR UNSEASONABLY
START TO THE WEEK.  THE MERCURY WILL STILL BE RECOVERING WEDNESDAY
BEFORE HEADING TO MORE AVERAGE LEVELS THURSDAY AND FRIDAY.  GFS (AND
TO A LESSER EXTENT THE ECMWF) IS PAINTING ANOTHER DEEPER LOW SCENARIO
NEAR INTERNATIONAL BORDER BY FRIDAY/SATURDAY...WITH ASSOCIATED
VOLUMINOUS PRECIPITATION AMOUNTS.  THIS SEEMS SUSPECT AT THIS TIME
AND HAVE ONLY INCLUDED LOW POPS MAINLY EASTERN FORECAST AREA FOR
NOW.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 650 PM CDT SAT JUL 12 2014

LINE OF THUNDERSTORMS WILL BE MOVING INTO KDVL SHORTLY AND KGFK
AND KTVF IN THE NEXT HOUR OR SO. WILL KEEP VCTS AND VFR CIGS AND
AMEND AS NEEDED AS ONLY THE HEAVIER CELLS HAVE BEEN REDUCING
CATEGORIES AT ALL. WINDS MAY BE AN ISSUE AS THE STORMS MOVE
THROUGH AS THERE HAVE BEEN SOME GUSTS UP AROUND 40 KTS IN SOME
PLACES. THE STORMS WILL WEAKEN AS THEY MOVE SOUTH AND CONDITIONS
WILL BE MORE QUIET AFTER 06Z. VFR CONDITIONS AND NORTHWEST WINDS
UNDER 12 KTS WILL PREVAIL THROUGH EARLY MORNING. WINDS WILL PICK
UP AGAIN AND BECOME RATHER BREEZY WITH GUSTS ABOVE 25 KTS BY MID
MORNING. WITH CONVECTIVE TEMPS IN THE MID 60S...THINK THAT MOSTLY
CLEAR SKIES WILL GIVE WAY TO A STRATOCU DECK BY MID DAY. CIGS
SHOULD REMAIN ABOVE 5000 FT.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$

UPDATE...JR
SHORT TERM...EWENS
LONG TERM...WJB
AVIATION...JR






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