Hazardous Seas Warning 27, NWS Medford, OR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
835 PM PDT TUE MAY 1 2012

.DISCUSSION...WINDS ARE DECREASING QUICKLY AND SKIES ARE BEGINNING
TO CLEAR AS WEAK SURFACE HIGH PRESSURE BUILDS IN OVER SW OREGON.
IT ALREADY FEELS CHILLY OUTSIDE AND WE ARE DOWN INTO THE MID 50S
AT MEDFORD, BUT INITIAL 02/00Z GUIDANCE STILL SHOWS US BOTTOMING
OUT AROUND 40 TONIGHT, WHICH IS RIGHT AT NORMAL. OUTLYING AREAS
WILL BE DOWN INTO THE 30S, BUT AM NOT EXPECTING ANY FROST OR
FREEZE IN THE MAIN WEST SIDE VALLEYS. THE MAIN TROUGH AXIS IS
MOVING ACROSS THE EAST SIDE RIGHT NOW, BUT MUCH OF THE ENERGY IS
NORTH OF US. WE COULD STILL SEE A STRAY SHOWER OVER THE NORTH
COAST OR UMPQUA THIS EVENING, BUT PRECIP CHANCES ARE ON THE
DECLINE AS THINGS STABILIZE. I DON'T SEE ANY NEED FOR UPDATES
TONIGHT.

HIGH CLOUD FROM THE NEXT SYSTEM IS ALREADY APPROACHING THE WATERS
AND WILL PROBABLY BECOME NOTICEABLE BY DAY BREAK TOMORROW. THE 00Z
NAM HAS SPED UP THE ARRIVAL OF PRECIP BY A FEW HOURS AND IS STILL
COMING IN QUITE WET ALONG THE COAST. THIS ISN'T SURPRISING GIVEN
THE GOOD MOISTURE TAP AND RELATIVELY HIGH PWAT VALUES WITH THIS
SYSTEM. SPECIFICALLY, THE 00Z NAM NOW SHOWS SEVERAL INCHES OF RAIN
FOCUSED OVER SOUTHERN CURRY COUNTY WEDNESDAY NIGHT, WHICH IS
HARDLY OUT OF THE QUESTION FOR THE AREA. I DID GET THINGS ROLLING
BY INCREASING PRECIPITATION AMOUNTS OVER THE COAST AND ADJACENT
RANGES FOR WEDNESDAY NIGHT, MORE IN LINE WITH A MODEL CONSENSUS.
THE NIGHT SHIFT CAN TRY TO NAIL IT DOWN FURTHER AS MORE 00Z MODEL
DATA ARRIVES. -WRIGHT

&&

.AVIATION...GENERALLY EXPECT VFR CONDITIONS THROUGH TOMORROW
MORNING AS SURFACE HIGH PRESSURE BUILDS OVER SW OREGON AND NORCAL.
STRATUS DOES EXIST OFFSHORE, BUT IT IS LESS CONTINUOUS THAN USUAL
AND 00Z MODEL DATA INDICATES THAT FLOW WILL BECOME LIGHT OFFSHORE
OVERNIGHT AT THE COAST. THIS WILL RETARD STRATUS FORMATION AT THE
COAST. LEFT IN A SCATTERED DECK AT KOTH, BUT KEPT VFR THROUGH THE
NIGHT. INLAND AREAS ARE LIKELY TOO DRY FOR ANY STRATUS FORMATION.
CLOUDS WILL INCREASE WITH LOWERING CIGS (STILL VFR) THROUGH THE
DAY TOMORROW AS A STRONG SYSTEM APPROACHES FROM THE WEST. RAIN IS
EXPECTED AT THE COAST LATE, SPREADING INLAND TOMORROW NIGHT.

&&

.PREV DISCUSSION... /ISSUED 216 PM PDT TUE MAY 1 2012/

SHORT TERM...THE BIGGEST CHANGE IN THE FORECAST WAS TO BUMP UP
THE COASTAL WATERS WINDS AND INCLUDE A GALE WATCH FOR LATE
WEDNESDAY NIGHT AND THURSDAY MORNING. A WIND ADVISORY MAY ALSO
NEED TO BE ISSUED ON THE EAST SIDE FOR THURSDAY AS A COLD FRONT
SWEEPS ACROSS THE REGION.

MADE ONLY MINOR CHANGES TO THE SHORT TERM FORECAST. THE INCOMING
WEATHER SYSTEM IS A LITTLE SLOWER SO HAVE LOWERED CLOUD COVER AND
POPS WEDNESDAY AFTERNOON. LOW TEMPERATURES WILL BE NEAR OR A
LITTLE ABOVE NORMAL OVER THE NEXT FEW DAYS DUE TO CLOUD COVER.
HIGH TEMPERATURES WILL BE A LITTLE BELOW NORMAL...ESPECIALLY
THURSDAY AND FRIDAY.

WINDS WILL INCREASE WEDNESDAY NIGHT AS A NEAR 1000 MB LOW
APPROACHES THE CENTRAL OREGON COAST. GALE WINDS ARE POSSIBLE LATE
WEDNESDAY NIGHT/EARLY THURSDAY MORNING FOR A 6-9 HOUR PERIOD.
WINDS AT THE COAST SHOULD REMAIN BELOW A HIGH WIND WARNING BUT
IT WILL BE QUITE GUSTY AT THE BEACHES AND POINTS. THURSDAY MORNING
SHOULD BE RELATIVELY MILD AS A WARM FRONT LIFTS ACROSS THE REGION
AHEAD OF THE LOW. BY THURSDAY AFTERNOON A COLD FRONT WILL SWEEP
THROUGH THE AREA BEHIND THE LOW WITH GUSTY WINDS ACROSS INLAND
AREAS...ESPECIALLY EAST OF THE CASCADES WHERE A WIND ADVISORY
MIGHT BE NEEDED. THURSDAY WILL BECOME A BRISK DAY WITH DECENT
COLD AIR ADVECTION.

THE COLD POOL ALOFT WILL BE OVER THE REGION ON FRIDAY WITH -27
DEGREES C (-17 F) AT 500 MB (18,000 FT). EXPECT SHOWERS TO PERSIST
ON FRIDAY WITH SNOW SHOWERS OVER THE HIGHER PASSES BUT WITH LITTLE
ACCUMULATION. MUCH OF THE AREA WILL ALSO SEE GUSTY AFTERNOON WINDS
ON FRIDAY DUE TO GOOD MIXING AND A SIGNIFICANT PRESSURE GRADIENT
WITH HIGH PRESSURE OFFSHORE AND LOW PRESSURE INLAND.

LONG TERM...THE MODELS ARE COMING MORE INTO AGREEMENT THIS WEEKEND
INTO EARLY NEXT WEEK. THE UPPER TROUGH WILL MOVE EAST OF THE
FORECAST AREA SATURDAY WITH DRY NORTHERLY FLOW SETTING UP IN THE
AFTERNOON. A FEW LEFTOVER SHOWERS MAY LINGER OVER THE NORTHERN
CASCADES EARLY SATURDAY MORNING, OTHERWISE IT WILL DRY WITH
DECREASING CLOUD COVER. OFFSHORE FLOW SETS UP SATURDAY NIGHT AND IS
EXPECTED TO LAST INTO EARLY NEXT WEEK KEEPING CONDITIONS DRY.
TEMPERATURES WILL BE COOL IN THE MORNINGS WITH THE COOLEST READINGS
IN THE VALLEYS. TEMPERATURES IN THE AFTERNOON WILL BE MILDER WITH
READINGS NEAR NORMAL. -PETRUCELLI

&&

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

CA...NONE.

PZ...GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR
     PZZ350-356-370-376.
     HAZARDOUS SEAS WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     MORNING FOR PZZ350-356-370-376.