000
FXUS65 KGGW 192030
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
230 PM MDT SUN MAY 19 2013

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY...
THE LOW PRESSURE CENTERS ARE CLOSING OFF AND BEGINNING TO STACK
OVER THE DAKOTAS. THE FOCUS OF PRECIPITATION IS WHERE THE
INVERTED SURFACE TROUGH NUDGES INTO THE WESTERN DAKOTAS AND
EASTERN COUNTIES OF NORTHEAST MONTANA. A BIT OF DRY SLOTTING
INITIALLY THROUGH THE CENTRAL COUNTIES OF NORTHEAST MONTANA...THEN
THE WESTERN COUNTIES AFTER MIDNIGHT WILL DIMINISH CHANCES THERE OF
ANY MEANINGFUL PRECIPITATION. EXPECT WIND TO PICK UP...MAINLY IN
THE EAST...AS THE SURFACE LOW RETROGRADES BACK TOWARDS OUR CWA.

MONDAY...THE WRAP-AROUND PRECIPITATION CONTINUES ON THE HEAVY
SIDE IN THE MORNING...BUT FINALLY AS THE LOW MOVES FARTHER EAST
THE INVERTED SURFACE TROUGH IS PULLED AWAY AND RAIN INTENSITY
DIMINISHES DURING THE AFTERNOON...BUT SHOULD CONTINUE MONDAY
NIGHT IN THE EAST. THE LOW MOVING AWAY WILL ALSO LIGHTEN THE WIND
IN THE WEST. BUT WIND IN THE EAST WILL BECOME STRONG FROM THE
NORTH DUE TO THE NEARNESS OF THE SURFACE LOW AND WIND ALOFT THAT
LINES UP. THIS WIND COULD EDGE FAR ENOUGH WEST FOR THE NEED OF A
WIND ADVISORY FOR THE EASTERN END OF FORT PECK LAKE. WILL TURN
THAT OVER TO THE OVERNIGHT SHIFT FOR ANOTHER LOOK. THERE COULD BE
SOME CLEARING IN THE NORTHWEST LATE THIS AFTERNOON AND EVENING.

TUESDAY...THE INFLUENCE OF THE LOW WILL BE TENACIOUS IN ITS REACH
INTO THE EASTERN COUNTIES OF NORTHEAST MONTANA QPF WILL LIGHT BUT
LOW OVERCAST CONTINUES. FOR THE WESTERN COUNTIES CONDITIONS WILL
BE INFLUENCED BY WEAK RIDGING BETWEEN THE DEPARTING LOW AND THE
NEXT STRONG LOW BUMPING UP AGAINST THE WASHINGTON/OREGON COAST.

TEMPERATURE DURING THE SHORT TERM WILL BE MILD AND VERY NEAR
NORMAL FOR THIS TIME OF YEAR. TEMPERATURES WILL TEND TO PUT A LID
ON THUNDERSTORM ACTIVITY...BUT WILL LEAVE ISOLATED TS IN DURING
THIS EVENINGS IN THE WEST WHERE THERE ARE A FEW GENERAL
THUNDERSTORMS. SCT

.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
UPPER LOW OVER THE NORTHERN PLAINS EXPECTED TO SLIDE EAST BY THE
BEGINNING OF THE EXTENDED PERIOD...TO BE REPLACED BY A NARROW
UPPER RIDGE AS ANOTHER CLOSED LOW SETTLES INTO THE PACIFIC
NORTHWEST. NORTHEAST MONTANA WILL BE IN THE BOUNDARY AREA WHERE
THE SOUTHWEST FLOW AROUND THE BASE OF THE LOW MEETS THE UPPER
RIDGE. MAIN CHANCE OF RAIN WILL BE ACROSS THE WESTERN ZONES
THROUGH MIDWEEK THEN SPREAD EAST INTO THE WEEKEND AS THE MODELS
BEGIN TO OPEN UP THE LOW. EBERT

PREVIOUS LONG TERM DISCUSSION...THE EXTENDED PERIOD CONTINUES WITH
UPPER LOWS TO OUR WEST AND EAST AND CONFUSED FLOW OVER NORTHEAST
MONTANA. THIS WILL CONTINUE UNTIL FRIDAY WHEN THE UPPER LOW IN THE
PACIFIC NORTHWEST SHIFTS CLOSER TO NORTHEAST MONTANA. THIS WILL
ENHANCE THE POSSIBILITY OF THUNDERSTORMS OVER THE WEEKEND.

TEMPERATURES WILL CONTINUE AROUND NORMAL WITH HIGHS HOVERING
AROUND 70 AND LOWS IN THE UPPER 40S TO LOWER 50S THROUGH THE PERIOD.

MODEL TRENDS SHOW A FAIRLY SMOOTH RUN TO RUN PERFORMANCE WHICH
ASSISTS WITH A HIGH CONFIDENCE. DID NOT GO TOO HIGH FOR POPS OVER
THE UPCOMING WEEKEND SINCE THERE IS A HINT OF RETROGRESSION
STARTING TO SHOW UP WITH FALLING HEIGHTS IN MOST ENSEMBLES OVER
THE NORTHEAST PACIFIC. THIS COULD LEAD TO THE UPPER LOW SINKING
FURTHER SOUTH AND WEST KEEPING NORTHEAST MONTANA DRIER. OVERALL
ENSEMBLES ARE FAIRLY GOOD SINCE WE ARE IN A CLIMATOLOGICAL NORMAL
PATTERN. RMOP ARE FAIRLY GOOD WITH THE LARGE SCALE FEATURES FOR
THE EXTENDED PERIOD. THEREFORE MODERATE TO GOOD CONFIDENCE IN THE
PERIOD FROM TUESDAY NIGHT THROUGH FRIDAY WITH SOME LOWER
CONFIDENCE IN THE WEEKEND PATTERN.            PROTON


&&

.AVIATION...
VFR BECOMING MVFR OVERNIGHT AS RAIN RETURNS TO THE REGION. GUSTY
NORTH WINDS ALSO EXPECTED TO PERSIST THROUGH MONDAY MORNING.

&&

.HYDROLOGY...
THE NEXT COUPLE OF DAYS WILL BE RATHER WET AS AN UPPER-LEVEL
TROUGH AFFECTS THE REGION. SEVERAL DISTURBANCES ASSOCIATED WITH THIS
TROUGH WILL PASS THROUGH WHICH WILL KEEP CHANCES FOR RAIN THROUGH
TUESDAY. MODEL GUIDANCE DEPICTS HIGH AMOUNTS OF MOISTURE WITH THIS
SYSTEM. AT THIS POINT THE ENVIRONMENT LOOKS FAVORABLE FOR SLOW-
MOVING STORMS WITH HIGHER PRECIPITATION IN LOCALIZED AREAS.

MOST OF THE BASINS IN NORTHEAST MONTANA WILL BE ABLE TO
ACCOMMODATE THIS AMOUNT OF MOISTURE. HOWEVER THERE IS SOME
CONCERN FOR RAPIDLY RISING STREAMS...FIELD FLOODING AND LOCALIZED
FLOODING IN TOWNS AS THE EVENT PERSISTS. SOME MINOR FLOODING MAY
BECOME AN ISSUE...ESPECIALLY FOR THE AREAS FROM WOLF POINT TO
CIRCLE AND EASTWARD INTO NORTH DAKOTA WHERE THE POTENTIAL FOR RAIN
IS HIGHER.


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

WEATHER.GOV/GLASGOW