Area Forecast Discussion
Issued by NWS Bismarck, ND

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 220951
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
451 AM CDT TUE JUL 22 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 445 AM CDT TUE JUL 22 2014

FORECAST ISSUES TODAY ARE PATCHY DENSE FOG THIS MORNING...AND
THUNDERSTORM CHANCES THIS AFTERNOON ALONG THE MONTANA BORDER COUNTIES.

THE RAINS OF MONDAY...AND LIGHT WINDS OVERNIGHT...HAVE BROUGHT
TEMPERATURES DOWN CLOSE TO THE DEW POINT LEVELS. PATCHY FOG HAD
FORMED AT TIOGA...WILLIAMS COUNTY...AT DICKINSON...AND AROUND
JAMESTOWN. PATCHES OF LOW CLOUD WERE ADVANCING SOUTH AND WEST
THROUGH THE STATE.

EARLY MORNING FOG WILL DISSIPATE BY MID MORNING WITH LOW CLOUD
PATCHES ALSO DRYING UP AS LOWER DEW POINT AIR MAKES ITS WAY IN AND
DAYTIME HEATING BEGINS.

FOR THIS AFTERNOON...A WEAK TROUGH OF LOW PRESSURE FORMS OVER
EASTERN MONTANA WITH A THERMAL RIDGE AXIS PUSHING NORTH JUST WEST
OF THE STATE LINE. THIS WILL BE SUFFICIENT FOR SOME SURFACE
CONVERGENCE...WHILE A WEAK MID LEVEL VORTICITY MAXIMA APPROACHES
WITH MID LEVEL FORCING. THE COMBINATION...IN SLIGHTLY INCREASING
UNSTABLE AIR...COULD LEAD TO ISOLATED THUNDERSTORMS...ESPECIALLY
OVER SOUTHWEST NORTH DAKOTA...BOWMAN-HETTINGER AREAS.

ANY CONVECTION DISSIPATES THIS EVENING WITH COOLER LOWS...IN THE 50S.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 445 AM CDT TUE JUL 22 2014

CLOSED UPPER LOW OFF THE WA/OR COASTS WILL BE THE DEFINING FORECAST
FEATURE FOR MOST OF THE EXTENDED PERIOD. THE UPPER LOW IS FORECAST
BY GFS/ECMWF TO MIGRATE ACROSS THE NORTHWEST US THROUGH IDAHO BY
THURSDAY THEN INTO SASK/MANT BY FRIDAY/SATURDAY. IT THEN MEANDERS
SOUTH ACROSS THE NORTHERN PLAINS SUNDAY INTO EARLY NEXT WEEK
BRINGING A COOLISH WEATHER PATTERN FOR JULY. AS THIS LOW BEGINS ITS
JOURNEY NORTHEAST INTO THE NORTHERN PLAINS AND THE PRAIRIE PROVINCES
OF CANADA IT WILL FLATTEN AN H500 RIDGE OVER THE NORTHERN PLAINS BY
THURSDAY. AT THE SURFACE THIS MEANS A COLD FRONT WILL APPROACH FROM
THE WEST AND FORCE A LOW LEVEL THERMAL RIDGE ACROSS WESTERN NORTH
DAKOTA THURSDAY. THIS SHOULD BE THE WARMEST DAY OF THE WEEK WITH
HIGHS MID 90S SOUTHWEST TO WEST CENTRAL. COLD FRONTAL PASSAGE
THURSDAY AFTERNOON/NIGHT WILL ALSO BRING A CHANCE OF THUNDERSTORMS
THROUGH THE REGION. CURRENTLY GOING 30-40 POPS FOR THIS. AFTER
FRIDAY WILL ONLY BE A SMALL CHANCE OF THUNDERSTORMS AS THE UPPER
LOW SLIDE SOUTHEAST KEEPING THE REGION ON ITS SOUTHERN SIDE WHICH
WILL BE GENERALLY DRY. SPOTTY 20 POPS FRIDAY THROUGH TUESDAY WITH
HIGHS IN THE 70S TO LOWER 80S.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 445 AM CDT TUE JUL 22 2014

PATCHES OF LOW CLOUD WITH IFR CIGS AND PATCHES OF FOG WITH IFR
VSBYS WERE OVER THE FORECAST AREA AS OF THIS WRITING. THESE HAVE
FORMED IN PART FROM THE RAIN OF MONDAY AND LIGHT WINDS OVERNIGHT.
HAVE ACCOUNTED FOR THIS IN THE TAFS...TO DISSIPATE AS LOWER DEW
POINT AIR WORKS IN AND DAYTIME HEATING BEGINS BY 15Z.

AN ISOLATED -TSRA IS POSSIBLE FROM KDIK THROUGH KISN AFTER 18Z.
OTHERWISE TAFS REFLECT VFR WEATHER...BUT A REFORMING OF PATCHY FOG
WILL BE POSSIBLE AGAIN ON WEDNESDAY MORNING.

&&

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

$$

SHORT TERM...JPM
LONG TERM...WAA
AVIATION...JPM







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