000
FXUS66 KMFR 052134
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
234 PM PDT SUN JUL 5 2009

.SHORT TERM...AN UPPER LEVEL TROUGH CENTERED OFF THE SOUTHERN
OREGON COAST AT 42N 132W IS BRINGING A SHORTWAVE INTO THE AREA THIS
EVENING AND TONIGHT. THIS TROUGH WILL REMAIN OFF THE COAST AND
SPIN VORTICITY MAXIMUM INTO THE REGION TONIGHT THROUGH THURSDAY.
THIS WILL BRING GUSTY AFTERNOON AND EVENING WINDS TO THE AREA
TODAY THROUGH THURSDAY. ALONG THE COAST AND INTO THE
UMPQUA...EXPECT PERIODS OF LOW CLOUDS THROUGH THURSDAY AS THESE
SHORTWAVES BRING ONSHORE WESTERLY FLOW.

THE SHORTWAVE MOVING INLAND THIS EVENING AND TONIGHT WILL BE
MAINLY DRY. THUNDERSTORMS ARE DEVELOPING AHEAD OF THIS DISTURBANCE
THIS AFTERNOON BUT ARE EXPECTED TO STAY NORTH AND EAST OF THE
AREA. THE MAIN EFFECTS OF THIS DISTURBANCE WILL BE TO BRING GUSTY
WINDS ACROSS THE AREA THIS AFTERNOON AND INTO THIS EVENING. WINDS
HAVE INCREASED OVER THE AREA WITH GUSTS OF AROUND 15 TO 20
MPH...MAINLY OVER HIGHER TERRAIN AND EAST OF THE CASCADES.
HOWEVER...WITH A MID LEVEL SOUTHERLY JET MOVING INTO THE WEST SIDE
THIS AFTERNOON AND THE SURFACE PRESSURE GRADIENT BECOMING
TIGHTER...GUSTY WINDS ARE EXPECTED IN VALLEY LOCATIONS WEST OF THE
CASCADES AS WELL. TONIGHT...EXPECT A LOWER TO MID LEVEL CLOUDS TO
PUSH INTO PORTIONS OF SOUTHERN OREGON WEST OF THE CASCADES DURING
THE EVENING AND OVERNIGHT. LIGHT DRIZZLE OR SHOWERS MAY BE
POSSIBLE WITH LOW CLOUDS LATE THIS EVENING AND TONIGHT ALONG THE
COAST.

MONDAY THROUGH THURSDAY...AS AN UPPER JET REMAINS OVER THE AREA
AND A TROUGH DEEPENS ALONG THE PAC NW COAST...EXPECT A COOLING
TREND AS HEIGHTS DECREASE AND EXPECT CONTINUED AFTERNOON GUSTY
CONDITIONS MONDAY INTO WEDNESDAY. WITH MODELS INDICATING
ADDITIONAL SHORTWAVE DISTURBANCES MOVING OVER THE
AREA....TUESDAY...WEDNESDAY AND THURSDAY...EXPECT A SLIGHT CHANCE
FOR SHOWERS OR THUNDERSTORMS IN THE REGION...MAINLY EAST OF THE
CASCADES. MODELS INDICATE THE BEST CHANCE FOR ANY THUNDERSTORM
ACTIVITY IN OUR AREA WILL BE TUESDAY AFTERNOON AND EVENING OVER
NORTHERN LAKE COUNTY. OTHERWISE...MODELS AGREE WITH KEEPING MOST
OF THE ACTIVITY NORTH AND EAST OF OUR AREA.

.LONG TERM...FRIDAY THROUGH SUNDAY...A RIDGE BUILDS INLAND WITH A
UPPER LOW REMAINING OFF THE COAST. THE RIDGE WILL BRING WARMER
TEMPERATURES WHILE THE LOW OFF THE COAST MAY BRING THE POTENTIAL
FOR PRECIPITATION. MODELS HAVE VARIED ON WHETHER ANY SHOWERS OR
THUNDERSTORMS WILL DEVELOP DURING THIS PERIOD. THE POSITION OF THE
LOW AND THE STRENGTH OF THE RIDGE WILL BE IMPORTANT FACTORS. HAVE
KEPT WITH A DRY SOLUTION WITH THE CURRENT FORECAST PACKAGE.
HOWEVER UNCERTAINTY REMAINS FOR THIS PERIOD.


&&

.AVIATION...A TROUGH MOVING INLAND WILL BRING CLOUDS AND GUSTY
WINDS TODAY WITH LOW CLOUDS SPREADING INLAND TONIGHT. WIDESPREAD MVFR
CIGS WITH AREAS OF IFR CIGS WILL PERSIST ALONG THE COAST WITH VFR
CONDITIONS INLAND EXPECTED THROUGH THIS AFTERNOON. WIDESPREAD MVFR
CIGS WILL SPREAD INLAND THIS EVENING ACROSS THE UMPQUA VALLEY IN
DOUGLAS COUNTY AND THEN ISOLATED MVFR CIGS WILL SPREAD INTO
PORTIONS OF THE ILLINOIS AND ROGUE VALLEY TONIGHT. ELSEWHERE VFR
WILL PREVAIL THROUGH TONIGHT. MONDAY MORNING...MVFR WITH ISOLATED
IFR WILL CONTINUE ALONG THE COAST WHILE INLAND...AREAS OF MVFR
CIGS WILL GRADUALLY LIFT TO VFR DURING THE MID TO LATE MORNING.

LOW LEVEL WINDS WILL BE GUSTY ACROSS THE AREA THIS AFTERNOON
THROUGH THIS EVENING.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.

CA...NONE.

PACIFIC COASTAL WATERS...NONE.

$$

CC