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wxman22 wrote:Even though i may be setting my hopes up for dissapointment its hard not to get a little excited when somthin like that shows up thats only 102hrs away and its the 12z run.For what its worth last week the GFS was the first model to show the cold core low. And then the other models started to latch on... Lets see what the 18z and more importantly what the 0z shows later tonight...
and the 18z run?wxgirl69 wrote:wxman22 wrote:Even though i may be setting my hopes up for dissapointment its hard not to get a little excited when somthin like that shows up thats only 102hrs away and its the 12z run.For what its worth last week the GFS was the first model to show the cold core low. And then the other models started to latch on... Lets see what the 18z and more importantly what the 0z shows later tonight...
when does the oz run?
ALASKA EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
154 PM EST MON NOV 30 2009
VALID 12Z FRI DEC 04 2009 - 12Z TUE DEC 08 2009
A MAJOR PATTERN CHANGE IS UNDERWAY IN THE MEDIUM RANGE DOMINATED
BY THE DEVELOPMENT OF A HIGH AMPLITUDE RIDGE OVER ALASKA AND THE
DEVELOPMENT OF A DEEP CLOSED LOW OVER THE NORTH CENTRAL PACIFIC
SOUTH OF THE ALEUTIANS.
WITH THE RIDGE BUILDING OVER ALASKA EARLY IN THE FORECAST...HIGH
PRESSURE BUILDS RAPIDLY ACROSS THE STATE ON FRIDAY/DAY 4 THAT
MOVES EAST OVER YUKON BY SATURDAY/DAY 5 WITH STRONG SOUTHERLY FLOW
COVERING THE WESTERN HALF OF THE STATE.
WHILE ONE SIGNIFICANT CYCLONE MOVES NORTHWARD FROM THE EASTERN
ALEUTIANS INTO THE BERING SEA ON SATURDAY/DAY 5...FARTHER NORTH
THAN ENVISIONED YESTERDAY...A SECOND MAJOR CYCLONE DEVELOPS OVER
THE NORTH CENTRAL PACIFIC AS WELL. THIS SYSTEM MAY OR MAY NOT
HAVE ENTRAINED MOISTURE FROM TYPHOON 26W NIDA...BUT WHETHER IT
DOES OR NOT...STILL LOOKS LIKE A MAJOR SYSTEM NO MATTER WHAT.
THE OVERNIGHT ENSEMBLE MEANS AS WELL AS THE OVERNIGHT OPERATIONAL
EUROPEAN/CANADIAN AND GFS RUNS PRODUCE A HUGE CYCLONIC CIRCULATION
SOUTH OF THE EASTERN ALEUTIANS BY SUNDAY/DAY 6. WITH HIGH
PRESSURE OVER THE NORTHEAST PACIFIC...A LONG FETCH OF
SOUTH/SOUTHEASTERLY FLOW BRINGS VERY HIGH THICKNESS VALUES INTO SW
ALASKA. AND THOSE VALUES CONTINUE TO RISE INTO MONDAY/DAY 7.
IN GENERAL...PREDICTABILITY IS TRENDING ABOVE AVERAGE WITH THE
ESTABLISHMENT OF A VERY LARGE SCALE PATTERN...SO MUCH SO THAT THE
00Z OPERATIONAL EUROPEAN/GFS/CANADIAN EACH PREDICTED A DEVELOPING
SURFACE HIGH NORTH OF ALASKA BY EARLY NEXT WEEK THAT THEN MOVES
INTO EXTREME NORTHWEST CANADA BY TUESDAY/DAY 8...AND SHOWS UP IN
THE ENSEMBLE MEANS WHICH IS A RARITY SO LATE IN THE FORECAST.
THE 12Z OPERATIONAL MODEL RUNS WERE PRETTY CONSISTENT WITH THE 00Z
RUNS. SO MUCH SO THAT I USED A LARGER COMPONENT OF THE
OPERATIONAL RUNS THAN USUAL FOR EVEN THE DAY 8 FORECAST...WITH A
COMBINATION OF THE 00Z EUROPEAN AND THE 12Z GFS...WITH A BIAS
TOWARD THE 00Z EUROPEAN. JUST AS EASILY COULD HAVE USED THE
CANADIAN MODEL AS WELL.
THE 12Z EUROPEAN IS SIMILAR TO THE PREVIOUS RUN...WITH THE MAJOR
LOW ON SUNDAY AND MONDAY SLIGHTLY FARTHER SOUTH THAN THE PREVIOUS
FORECAST. THE ONLY SIGNIFICANT DIFFERENCE IS LATE IN THE FORECAST
WITH A POLAR AIRMASS MOVING INTO NORTHWEST AND NORTHCENTRAL
CANADA.
KOCIN
wxgirl69 wrote:and the 18z run?wxgirl69 wrote:wxman22 wrote:Even though i may be setting my hopes up for dissapointment its hard not to get a little excited when somthin like that shows up thats only 102hrs away and its the 12z run.For what its worth last week the GFS was the first model to show the cold core low. And then the other models started to latch on... Lets see what the 18z and more importantly what the 0z shows later tonight...
when does the oz run?
EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
233 PM EST MON NOV 30 2009
VALID 12Z THU DEC 03 2009 - 12Z MON DEC 07 2009
12Z CYCLE UPDATE...
THE PRIMARY CHANGES ON THE 12Z MODEL CYCLE ARE THE MODELS HAVE
AMPLIFIED THE WESTERN ATLANTIC DEEP LAYER RIDGE ON DAY FOUR AND
FIVE...WHICH ALLOWS THE DEVELOPMENT OF A WAVE FURTHER WEST THAN
THE 00Z GUIDANCE SUITE. SINCE THE 12Z ECMWF/GFS/CANADIAN
GLOBAL/UKMET SHOW A WAVE DEVELOPING...AN UPDATE TO SHOW A LOW
DEVELOPING OVER THE WESTERN ATLANTIC ON SAT DEC 5 IS SHOWN...WITH
THE PRELIM SOLUTION BLENDED WITH THE 12Z ECMWF TO DERIVE THE FINAL
SOLUTION. THE 12Z GFS PARALLEL SHOWS A MAJOR STORM FOR COASTAL NEW
ENGLAND...AND THIS WILL BE A TEST OF ITS SKILL...AS IT IS AN
OUTLIER SOLUTION.
IN THE PACIFIC NORTHWEST AND OFF THE WEST COAST...A WIDE SPREAD OF
SOLUTIONS PERSISTS. THE 12Z GFS CONTINUES ON THE FAST SIDE WITH A
CLOSED LOW EMERGING FROM THE ROCKIES ACROSS THE NORTHERN PLAINS.
THIS IS COMPLETELY CONTRADICTED BY THE GFS PARALLEL...WHICH LIKES
THE UKMET/CANADIAN IDEA OF A FURTHER WEST CLOSED 500 MB LOW
DEVELOPING OVER THE NORTHWEST US. THE 12Z ECMWF TRENDED FURTHER
EAST WITH ITS LOW DEVELOPMENT ON FRI TO EARLY SAT...BUT STALLS THE
LOW OFF THE WEST COAST. ON SAT-SUN IT MERGES THIS LOW WITH
ANOTHER LOW UNDERCUTTING THE HIGH AMPLITUDE EAST PACIFIC RIDGE AND
PRODUCES A WET PERIOD FOR COASTAL CENTRAL-NORTHERN CA SUN
NIGHT-EARLY MON. WITH THE MODELS GRADUALLY AGREEING ON THE HIGH
AMPLITUDE CLOSED HIGH ALOFT OVER THE NORTHEAST PACIFIC/ALASKA (500
MB HEIGHTS 2-3 STD DEVIATIONS ABV NORMAL IN THE ECMWF/GEFS
MEANS)...ODDS ARE INCREASING OF A CLOSED LOW DEVELOPING FURTHER
SOUTH OVER THE NORTHWEST/ADJACENT COASTAL WATERS
AND A LIKELY REX BLOCK (HIGH NORTH OF A CLOSED LOW) DEVELOPING.
FINAL PROGS BLENDED THE PRELIM WITH 30% OF THE 12Z ECMWF TO
PROVIDE BETTER DEFINITION/DEEPER INTENSITY TO THE LOW OFF THE
PACIFIC NORTHWEST/NORTHERN CA COAST.
PRIOR DISCUSSION...
MODEL AND ENSEMBLE GUIDANCE ALL SHOW PRONOUNCED AMPLIFICATION OF
THE NORTHEAST PACIFIC DEEP LAYER RIDGE. THIS LEADS TO A
DOWNSTREAM DEVELOPMENT OF A WESTERN US TROUGH AND THE DEVELOPMENT
OF A SFC ANTICYCLONE IN WESTERN CANADA AS A DOME OF COLD AIR
BUILDS IN WESTERN CANADA AND STARTS MOVING INTO THE NORTHWESTERN
US. THE PRELIMINARY FRONTS AND PRESSURES ARE PRIMARILY A BLEND OF
THE NCEP AND ECMWF ENSEMBLE MEANS...WITH MINORITY CONTRIBUTIONS OF
THE 00Z ECMWF/CANADIAN/UKMET SOLUTIONS.
THE MODELS ARE IN GOOD AGREEMENT ON THE EASTERN US CYCLONE DAYS
3-4 AS IT MOVES NORTH ACROSS NY/NEW ENGLAND AND UP INTO CANADA.
THE 06Z GFS HAS SLOWED DOWN TO MATCH THE TIMING OF THE
ECMWF/CANADIAN/UKMET/RESPECTIVE ECMWF/NCEP ENSEMBLE MEAN. WITH
GOOD CLUSTERING OF SOLUTIONS...A BLEND OF THE MODELS WAS USED.
THE DIFFERENCES START TO DEVELOP UPSTREAM OFF THE WEST COAST.
PHASING DIFFERENCES AMONG MODEL/ENSEMBLE SOLUTIONS LEADS TO LARGE
SPREAD OF POSSIBLE SCENARIOS. WITH INITIAL ENERGY PROGRESSING
FROM THE EASTERN PACIFIC INTO NORTHWEST US... THE 00Z GFS WAS ON
THE FAST EDGE OF GUIDANCE AND WAS NOT USED AS THE 06Z GFS HAS
SLOWED TOWARDS THE TOWARD THE CONSENSUS CLUSTER. IN ADDITION TO
TIMING DIFFERENCES...THE ECMWF HAS FORMED A DEEPER CLOSED LOW
SFC/ALOFT ON THE WESTERN EDGE OF THE GUIDANCE ENVELOPE THAN THE
GFS/CANADIAN/UKMET/EARLIER ECMWF RUNS AND THE ECMWF ENSEMBLE MEAN.
7 OF THE 50 ECMWF ENSEMBLE MEMBERS HAVE A CLOSED 500 MB LOW LIKE
THE OPERATIONAL ECMWF...WITH WIDE DISPERSION ACROSS THE NORTHEAST
PACIFIC FRIDAY AND THEN ONSHORE SATURDAY. A MULTI-MODEL AND
ECMWF/NCEP ENSEMBLE MEAN CONSENSUS WAS USED TO MITIGATE THE
DIFFERENCES.
MULTI-DAY MEANS SUGGEST THE CORE OF POSITIVE HGT ANOMALIES
UPSTREAM SHOULD BE OVER THE GULF OF AK TO THE SOUTHERN AK
COASTLINE... WHICH TELECONNECTS TO A MEAN TROF EXTENDING SOUTHWEST
FROM HUDSON BAY ACROSS THE NORTHERN HIGH PLAINS/ROCKIES INTO THE
GREAT BASIN. THIS IN TURN SUPPORTS COLDER THAN NORMAL TEMPS IN
THE NORTHWEST US TO THE NORTHERN PLAINS AND EVENTUALLY UPPER MS
VALLEY. CONVERSELY...THIS PATTERN FAVORS THE DEVELOPMENT OF WARMER
THAN NORMAL TEMPS ACROSS THE SOUTHEAST/FL ON DAY SEVEN AND BEYOND.
THE CANADIAN/UKMET AND SEVERAL NCEP/ECMWF ENSEMBLE MEMBERS SHOW
THE DEVELOPMENT OF A NORTHWEST US CLOSED 500 MB LOW SAT...AND THE
06Z GFS BY SUN. THE CANADIAN MODEL BECOMES THE SOUTHERN OUTLIER
ON SUN DEC 06 AND MON DEC 07. ON DAYS 4-5...THE CANADIAN IS
INCLUDED WITH THE UKMET AND ENSEMBLE MEANS IN SHOWING DEVELOPMENT
OF THE NORTHWEST US TROUGH. ON DAY 7...THE CANADIAN WAS
DISCONTINUED IN FAVOR OF GREATER WEIGHTING OF THE MEANS.
PETERSEN
Portastorm wrote:Oh my ... perhaps the 12z GFS was on to something after all.
While the 12z Euro doesn't show precip over SE Texas between the 96-120 hour time frame ... it does show much more moisture in west Texas at multiple levels of the atmosphere. The trend here suggests that maybe there WILL be some energy coming down the backside of the trough and impacting Texas on Friday when temps will be cold enough for sleet and snow for many of us. Wow! This is going to be really interesting to watch!
http://www.meteo.psu.edu/~gadomski/ECMWF_12z/ecmwfloop.html
my Cowboys my Rockets my Astros Weatherdude20 wrote:http://www.srh.noaa.gov/fwd/#
content 5 (Snow?) show NWS prediction of snow for Dfw Area Wednesday morning
my Cowboys my Rockets my Astros 
Extremeweatherguy wrote:And so it begins..
Snow is officially now falling in and around El Paso.
http://www.youtube.com/watch?v=zrZGMV8TZLQ
Hopefully we will all be lucky enough to see scenes like this one in the coming days.
0z run is 6PM Central Time during Savings time.. That is when the actual model collects the data and begins.. By the time its done analysing the data and creating the maps available by the internet is different for the NAM and the GFS.. The NAM begins around 7:30ish, the GFS about 9:30.. For the NAM it takes about an hour, the GFS about an hour and a half..
The 18z run is noon Central Time during savings time.. NAM begins about 1:30 or so and the GFS about 3:30...
Some think that the 6z and 18z runs are not as accurate.. Many times you will be watching a setup and a 6z or 18z run will go crazy way off, just to bring the setup back and 0z or 12z.. It is kind of weird..
Josh
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