Hazardous Seas Warning 41, NWS Medford, OR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
826 PM PDT TUE JUL 31 2012

.DISCUSSION...SKY REMAINS CLEAR ACROSS OUR FORECAST AREA THIS
EVENING. IN A FEW HOURS AFTER SUNSET, EXPECT MARINE LAYER TO
DEEPEN AT THE COAST WITH LOW CLOUDS RETURNING AND FILLING MOST OF
THE COASTAL VALLEYS BY MIDNIGHT. NOT CERTAIN YET ON WHETHER ANY
LOW CLOUDS WILL SPREAD INTO ROSEBURG BUT NORTHWESTERN DOUGLAS
COUNTY LOOKS MORE LIKELY TO SEE LOWER CLOUDS, MAINLY LATE TONIGHT
AROUND SUNRISE.

NEW MODEL RUN IS CONSISTENT WITH RIDGE NUDGING NORTH INTO SOUTHERN
OREGON THIS WEEKEND WITH A GOOD CHANCE AT SEEING 100 AT THE
MEDFORD AIRPORT ON SATURDAY. /FB

&&

.AVIATION...AN UPPER LEVEL TROUGH WILL DEEPEN THE MARINE LAYER
THIS EVENING. EXPECT MVFR CEILINGS TO IMPACT THE COAST SHORTLY
AFTER SUNSET. COASTAL CEILINGS WILL DROP TO IFR LATER TONIGHT
WHILE LCL MVFR CEILINGS MOVE INTO THE UMPQUA BASIN NEAR SUNRISE.
ALL CEILINGS WILL BURN OFF LATE WEDNESDAY MORNING OR EARLY
WEDNESDAY AFTERNOON. ALL OTHER INLAND LOCATIONS REMAINING VFR
THROUGH WEDNESDAY. NO THUNDERSTORMS ARE EXPECTED THROUGH FRIDAY IN
A FAIRLY STABLE AND PERSISTENT WEATHER PATTERN. /FB

&&

.PREV DISCUSSION... /ISSUED 300 PM PDT TUE JUL 31 2012/

DISCUSSION...VERY SUBTLE DIFFERENCES BETWEEN THE WEATHER PATTERN
TODAY FROM YESTERDAY. THE MARINE LAYER BURNED OFF AT THE COAST
SEVERAL HOURS EARLIER TODAY WHILE IT HELD OVER THE UMPQUA BASIN
UNTIL LATE MORNING ONCE AGAIN. TEMPERATURES OVER INLAND AREAS ARE
GENERALLY 2 TO 3 DEGREES WARMER THAN THEY WERE YESTERDAY. A WEAK
TROUGH IS PASSING THROUGH TO THE NORTH THIS AFTERNOON. THIS WILL
CAUSE TWO SLIGHT CHANGES IN THE SHORT TERM FORECAST. THE FIRST IS
THAT AFTERNOON WINDS WILL BE SLIGHTLY GUSTIER TODAY, ESPECIALLY
OVER THE HIGHER TERRAIN ON THE EAST SIDE. THE SECOND ITEM IS A
DEEPER MARINE LAYER OVERNIGHT TONIGHT. THIS WILL ALLOW IT TO MAKE
IT SOMEWHAT FURTHER INLAND AND PERSIST A FEW HOURS LONGER.
THERE WILL BE HARDLY ANY NOTICEABLE CHANGE TO THE WEATHER UNTIL
FRIDAY. TEMPERATURES WILL CONTINUE TO WARM BY A DEGREE OR TWO EACH
DAY WITH DRY CONDITIONS. ON FRIDAY THE POTENT UPPER LEVEL TROUGH
MAKES ITS WAY INTO THE NORTHERN PLAINS FROM CANADA. THE VERY
SOUTHERN END OF THIS TROUGH WILL CLIP OUR AREA HELPING TO DEEPEN
THE MARINE LAYER ENOUGH TO PRODUCE SOME DRIZZLE FOR THE NORTH
COAST FRIDAY MORNING. BUT AS THIS TROUGH MOVES EAST, IT WILL ALLOW THE
RIDGING OVER THE DESERT SOUTHWEST TO BUILD OVER US ON SATURDAY.
SATURDAY TEMPERATURES WILL CLIMB VERY QUICKLY AND CONFIDENCE
CONTINUES TO GROW THAT MANY PLACES, INCLUDING MEDFORD, WILL
FINALLY CRACK THE CENTURY MARK.
THIS RIDGE WILL ALSO PUT OUR AREA UNDER SOUTHERLY FLOW SATURDAY
INTO SUNDAY. THIS SHOULD BRING IN ENOUGH MOISTURE TO TRIGGER
THUNDERSTORMS SATURDAY AND SUNDAY AFTERNOONS. THE EC AND GFS
CONTINUE TO SHOW SUBTLE, YET SIGNIFICANT DIFFERENCES THAT WILL
DICTATE WHEN AND WHERE THE STORMS WILL FIRE. AT THIS POINT, WE
HAVE A FAIRLY BROAD AREA OF SLIGHT CHANCE THUNDER IN THE FORECAST
FOR SUNDAY. WE WILL CONTINUE TO REFINE THIS AREA AS THE DETAILS
BECOME CLEARER. SUNDAY COULD BE AS WARM AS SATURDAY UNLESS CLOUD
COVER FROM STORMS RESTRICTS THE HEATING.
STORMS MAY CONTINUE INTO MONDAY. TUESDAY AND THE REST OF THE
EXTENDED LOOKS TO TAKE US BACK INTO THE DRY SOUTHWESTERLY FLOW.
THIS SHOULD ONCE AGAIN RETURN OUR TEMPERATURES TO AT OR SLIGHTLY
BELOW SEASONAL.

AVIATION...MOST CLOUDS HAVE CLEARED ALONG THE COAST AND UMPQUA
BASIN. AN UPPER TROUGH WILL DEEPEN THE MARINE LAYER THIS
EVENING...AND EXPECT MVFR CEILINGS TO IMPACT THE COAST A FEW HOURS
BEFORE SUNSET. COASTAL CEILINGS WILL DROP TO IFR LATER
TONIGHT...WHILE MVFR CEILINGS MOVE INTO THE UMPQUA BASIN NEAR
SUNRISE. ALL CEILINGS WILL BURN OFF LATE WEDNESDAY MORNING OR
EARLY WEDNESDAY AFTERNOON...WITH ALL OTHER INLAND LOCATIONS
REMAINING VFR THROUGH WEDNESDAY. NO THUNDERSTORMS ARE EXPECTED
THROUGH FRIDAY IN A FAIRLY STABLE AND PERSISTENT WEATHER PATTERN.

&&

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

CA...NONE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT FRIDAY FOR PZZ356.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT FRIDAY
     FOR PZZ356.
     GALE WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY EVENING FOR
     PZZ376.
     SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 AM PDT WEDNESDAY FOR
     PZZ376.
     HAZARDOUS SEAS WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
     EVENING FOR PZZ376.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT
     WEDNESDAY FOR PZZ376.

08/99/99