As I said early last week we do have a major storm coming to the Eastern US. The biggest questions are when and how much? It appears the timing is looking towards the end of the week, perhaps Friday.
While some forecasters use only data that misses come crucial aspects of a forecast. Like, is that computer model handling a situation well? If not, how to reconcile the differences into a forecast that will benefit the most amount of people.
Over the next few days this system will affect the west and the Rockies producing a major winter storm across the Rocky Mountain Region.
The Eastern US will see the storm system complex now over the Rockies being influenced by other systems. We will keep you up-to-date over these changes and any relevant information like storm warnings.
Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
407 PM EDT Sun Oct 27 2013
Valid 00Z Mon Oct 28 2013 – 00Z Wed Oct 30 2013
…Heavy rain possible over parts of the Central Plains…
…Temperatures will be 10 to 25 degrees below average for parts of the
Northern High Plains…
A developing deep upper-level low over the Pacific Northwest will dig
southward to the Great Basin by Tuesday. In the meantime a front
extending from the Upper Great Lakes to the Central Plains then into the
Northern Rockies will move off the Northeast and Mid-Atlantic Coast by
Monday night. The boundary will produce light rain over parts of the
Upper Great Lakes that will move into the Northeast/Lower Great Lakes by
Monday morning, with snow at the higher elevations of the interior
Northeast. The snow will end overnight Monday.
The digging upper-level trough will produce light snow over parts of the
Northern High Plains and expand into the Great Basin, post frontal, by
Monday and into parts of the Higher elevations of eastern California into
the Central Rockies by Tuesday morning. As the upper-level trough
deepens, moisture from the Western Gulf of Mexico will move northward over
the Southern/Central Plains. A much weaker upper-level impulse moving
from the Central Gulf Coast to off the Southeast Coast will trigger
evening showers and thunderstorms, on Sunday evening, along with
nighttime rain over parts of the Central Gulf Coast into the Tennessee
Valley/Central Appalachians Monday into Monday evening.
The moisture will overrun the east-west front over the Plains/Mississippi
Valley producing showers and thunderstorms over parts of the
Central/Southern Plains Monday night into Tuesday. Rain will develop
north of the boundary on Tuesday from parts of the Central High Plains to
the Middle Mississippi Valley.
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1159 AM EDT SUN OCT 27 2013
VALID 12Z WED OCT 30 2013 – 12Z SUN NOV 03 2013
THE MEDIUM RANGE FORECAST…WHICH INCLUDES A LARGE-SCALE FLOW
PATTERN CHANGE…LOOKS TO BE IN FULL SWING THROUGH THIS DAY 3-7
THE 27/00Z ECENS/NAEFS AND DETERMINISTIC ECMWF AND CANADIAN RUNS
WERE IN VERY GOOD AGREEMENT…EVEN WITH SMALLER SCALE DETAILS OVER
THE GREAT LAKES–OUT THROUGH DAY 6. WPC MANUAL SURFACE GRAPHICS
CONTINUE WITH THE MIDWEST/GREAT LAKES OPEN WAVE CYCLONE SOLUTION
THAT QUICKLY WRAPS AND INTENSIFIES DOWNSTREAM OVER SOUTH CENTRAL
THE 27/00Z DETERMINISTIC GFS CONTINUES TO PRODUCE A DEEP OCCLUDED
CYCLONE OVER THE MID MISSOURI VALLEY AND REMAINS A FASTER SOLUTION
THAN ITS MEAN THROUGH THE UPPER GREAT LAKES. IN SIMPLE TERMS…IT
ALL BOILS DOWN TO THE JET STREAK EJECTING OUT OF THE SOUTH CENTRAL
ROCKIES AROUND 31/00Z (DAY 3.5) AND THE GFS ALLOWING NEARLY ALL
THE ENERGY/VORTICITY ROLLING NORTHEASTWARD WITH THAT FEATURE. THE
DETERMINISTIC ECMWF/CANADIAN ARE IN GOOD AGREEMENT WITH THE JET
STREAK BUT ARE ABOUT 12 HOURS SLOWER THAN THE GFS WITH THE BULK OF
THE VORTICITY EJECTING OUT OF THE TX/OK PANHANDLES AND SWRN
AS A RESULT…THE DETERMINISTIC GFS IS THE FASTEST SURFACE
SOLUTION ACROSS THE LOWER MS VALLEY AND DOWNSTREAM ALONG THE
EASTERN SEABOARD DAY 6. TO MAINTAIN CONTINUITY OVER THE LAST 3-4
DAYS…WE DISCOUNTED THE GFS TODAY.
I wanted everyone to see that these discussions are widely varied and accounts for some of the confusion. The airmasses are fluid and subject to changes in the 3-dimensions. Over the weeks and through this winter, I will keep you abreast of the weather and some Meteorology to help you understand it.
Please check the above the dynamic models which will give you a look at the storms in motion and including watch areas.
National High and Low Temperature (for the contiguous United States)
NWS Weather Prediction Center, College Park, MD
Issued 8 pm EDT Sunday, October 27, 2013
High Temperature for Sunday, October 27, 2013
(as received by 8 pm EDT October 27)
94 at El Centro, CA
Low Temperature for Sunday, October 27, 2013
(as received by 8 pm EDT October 27)
11 at Stanley, ID