NWS Climate Prediction Center



Click on product title to go to product page. Move cursor over product parameter name to display the graphic -- click to enlarge.
 
 
 
 
 
 
 
Latest 6 to 10 Day Temperature Outlook

Prognostic Discussions


Valid: Dec 18 - 22, 2019 (6-10 Day Outlook)
Valid: Dec 20 - 26, 2019 (8-14 Day Outlook)
Issued: Dec 12, 2019


Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks 
NWS Climate Prediction Center College Park, MD 
300 PM EST Thu December 12 2019 
 
6-10 DAY OUTLOOK FOR DEC 18 - 22 2019 
 
Today's GEFS, ECMWF, and Canadian ensemble mean solutions are in generally good  
agreement on the 500-hPa height pattern over the forecast domain for the 6-10  
day period. A mean trough is forecast across most of mainland Alaska. This  
trough is expected to extend south across the eastern Pacific off the west  
coast of the CONUS. Downstream, mean ridging is predicted across the  
west-central CONUS while a trough is expected over the Northeast. The manual  
500-hPa height blend favors the 0z ECMWF Ensemble mean and features above  
normal heights across the central, southwestern, and interior northwestern  
CONUS. Below normal heights are indicated across the Northeast and much of mainland Alaska. Above normal heights are indicated for much of the Aleutians. Below normal temperatures are favored across much of the Eastern CONUS and Gulf Coast Region due to mean troughing over eastern North America. The highest probabilities of below normal temperatures (greater than 60%) are indicated for the Northeast where negative height anomalies are expected to be the greatest. Conversely, there are enhanced probabilities of above normal temperatures across he West Coast ahead of a mean trough offshore. Above normal temperatures are also favored for much of the Central and Northern High Plains due, in part, to the potential for downslope flow. Predicted mean troughing leads to enhanced probabilities of near to below normal temperatures across most of mainland Alaska. However, above normal temperatures are favored for the Aleutians, the Panhandle, and parts of coastal mainland Alaska due to below normal Sea Ice Extent and above normal SSTs for many of these areas. There is unusually high confidence for above normal precipitation across the West Coast of the CONUS as a trough approaches the coast from the Eastern Pacific. Probabilities of above normal precipitation exceed 80 percent across parts of Northern California due to excellent agreement between dynamical model guidance and teleconnections from the upstream trough offshore. Elsewhere, drier than normal conditions are favored for most of the remainder of the CONUS from the Great Basin to the East Coast as surface high pressure dominates much of the country. However, above normal precipitation is favored across the central and southern Florida peninsula due to potential stalled frontal boundaries underneath mean low level northeasterly flow. Near to below normal precipitation is likely across much of mainland Alaska as a mean trough is expected to push the storm track south of much of the state. However, above normal precipitation is slightly favored for parts of southwestern Alaska and the southern Panhandle closer to the predicted mean storm track. The official 6-10 day 500-hPa height blend consists of 5% of Today's 0z GFS Ensemble Mean centered on Day 8, 10% of Today's 6z GFS Ensemble Mean centered on Day 8, 5% of Today's operational 0z GFS centered on Day 8, 50% of Today's 0z European Ensemble Mean centered on Day 8, 10% of Today's operational 0z ECMWF centered on Day 8, and 20% of Today's 0z Canadian Ensemble Mean centered on Day 8 FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Above average, 4 out of 5, due to good agreement among most of the models on the 500-hPa pattern and associated surface tools. 8-14 DAY OUTLOOK FOR DEC 20 - 26 2019 During the week-2 period, model uncertainty increases across Alaska as today's GEFS ensemble means build a 500-hPa ridge across much of mainland Alaska while today's 0z ECMWF and Canadian ensemble means maintain a trough across much of the same region. Agreement is better farther to the south as a trough over the Eastern Pacific is forecast to slowly progress toward the west Coast of the
CONUS. Mean ridging is forecast over the west-central CONUS. This ridge is generally expected to flatten by the end of the week-2 period. Mean low-amplitude flow is forecast across much of the central and eastern CONUS behind a departing trough over the Canadian Maritimes. The low amplitude flow depicted across much of the CONUS is due, in part, to large uncertainties among the component ensemble members. Unusually large spread in the predicted AO index is noted among the GEFS ensemble members with some members showing the index turning sharply negative toward the end of the period. This would signal a potential pattern change toward the end of week-2 and will need to be monitored to see if better agreement emerges in future model runs. Above normal temperatures are favored for the central and western CONUS underneath predicted low amplitude flow. However, above normal temperature probabilities are tempered for much of the northern tier due to a potential shift to a colder pattern near the end of week-2. Below normal temperatures are favored for the Northeast in association with departing trough over eastern North America. Near to below normal temperatures are slightly favored for most of central and northern mainland Alaska consistent with today's ECMWF and Canadian ensemble mean solutions. Above normal temperatures are favored for parts of southern Alaska due, in part, to SST and Sea Ice considerations. As a trough progresses from the Eastern Pacific to the West Coast, above normal precipitation remains strongly favored for much of the Western CONUS. The highest probabilities above normal precipitation (greater than 70%) are indicated for Northern California as teleconnections from the mean trough position strongly favors an active pattern. High probabilities of above normal precipitation (greater than 60%) also extend to parts of southern Calfornia as the trough approaches the coast. Low confidence exists across most of the central CONUS underneath mean low amplitude flow and fairly high uncertainty among the component ensemble members. Drier than normal conditions are favored for much of the east coast as surface high pressure is expected to dominate for much of the period behind a departing trough over the Canadian Maritimes. The potential for trailing frontal boundaries lead to enhanced probabilities of above normal precipitation for the southern Florida Peninsula. Model uncertainty is great across Alaska, leading to only modestly enhanced probabilities of above normal precipitation across much of the state, consistent with calibrated guidance from the GEFS and ECMWF reforecasts. The official 8-14 day 500-hPa height blend consists of: 5% of Today's 0z GFS Ensemble Mean centered on Day 11, 10% of Today's 6z GFS Ensemble Mean centered on Day 11, 5% of Today's operational 0z GFS centered on Day 11, 60% of Today's 0z European Ensemble Mean centered on Day 11, and 20% of Today's 0z Canadian Ensemble Mean centered on Day 11 FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: About average, 3 out of 5, due to very good agreement over the western CONUS among the precipitation tools offset by increasingly large uncertainties on the overall pattern later in week-2. FORECASTER: Scott H Notes: Automated forecasts are issued on Saturday and Sunday. Occasionally manual intervention is necessary to address quality control and consistency issues. In these cases, forecasts are manually drawn but a full discussion is not issued. The notation for the categorical forecast indicated on the maps is the same as that in the tables: A-above N-near normal B-below The temperature map shows regions with > 33% chance of being warmer (orange, "A"), colder (blue, "B"), or close to (unshaded, "N"). Historical average values for the calendar period of the forecast (dashes, "f").  Labels on the shaded lines give the probability (> 33%) of the more likely category (B or A). Probability of N is always < 40%. The precipitation map shows regions with > 33% chance of being wetter (green, "A"), drier (tan, "B"), or close to (unshaded, "n"). Historical median values for the calendar period of the forecast (dashes, "inches").  Labels on the shaded lines give the probability (> 33%) of the more likely category (B or A). Probability of N is always < 40%. In the southwest and other climatologically dry regions - there will be a greater than 33.3% chance of no precipitation and occasionally even a normal (i.e. Median) value of zero - especially during the dry seasons.  In such cases a forecast of near normal is effectively a forecast of little or no precipitation. The climate prediction center uses 1981-2010 base period means for temperature...precipitation...and 500-hpa heights as reference in the climate outlooks. The next set of long-lead monthly and seasonal outlooks will be released on December 19. Analogs to the 5 day mean observed pattern centered 3 days ago (D-3) for the region from 20N to 70N latitude and 175E to 60W longitude include the 5 day periods centered on the following dates: 19581127 - 19821124 - 19821212 - 19931226 - 19601224 Analogs to the 7 day mean observed pattern centered 4 days ago (D-4) for the region from 20N to 70N latitude and 175E to 60W longitude include the 7 day periods centered on the following dates: 19821212 - 19581128 - 19821124 - 19601222 - 20071124 6-10 DAY OUTLOOK TABLE Outlook for Dec 18 - 22 2019 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A A OREGON A A NRN CALIF A A SRN CALIF A A IDAHO A A NEVADA A A W MONTANA A B E MONTANA A B WYOMING A B UTAH N B ARIZONA A B COLORADO A B NEW MEXICO A B N DAKOTA A B S DAKOTA A B NEBRASKA A B KANSAS A B OKLAHOMA N B N TEXAS N B S TEXAS B B W TEXAS N B MINNESOTA B B IOWA N B MISSOURI N B ARKANSAS N B LOUISIANA B B WISCONSIN B B ILLINOIS B B MISSISSIPPI B B MICHIGAN B B INDIANA B B OHIO B B KENTUCKY B B TENNESSEE B B ALABAMA B B NEW YORK B B VERMONT B B NEW HAMP B B MAINE B B MASS B B CONN B B RHODE IS B B PENN B B NEW JERSEY B B W VIRGINIA B B MARYLAND B B DELAWARE B B VIRGINIA B B N CAROLINA B B S CAROLINA B B GEORGIA B B FL PNHDL B B FL PENIN B A AK N SLOPE N N AK ALEUTIAN A N AK WESTERN B N AK INT BSN B B AK S INT A B AK SO COAST A N AK PNHDL A N 8-14 DAY OUTLOOK TABLE Outlook for Dec 20 - 26 2019 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A A OREGON A A NRN CALIF A A SRN CALIF A A IDAHO A A NEVADA A A W MONTANA A A E MONTANA A N WYOMING A A UTAH A A ARIZONA A A COLORADO A A NEW MEXICO A A N DAKOTA A A S DAKOTA A N NEBRASKA A N KANSAS A N OKLAHOMA A N N TEXAS A N S TEXAS A N W TEXAS A N MINNESOTA A N IOWA A N MISSOURI A A ARKANSAS A N LOUISIANA A B WISCONSIN A N ILLINOIS A A MISSISSIPPI A B MICHIGAN A N INDIANA A N OHIO A N KENTUCKY A N TENNESSEE A N ALABAMA A B NEW YORK B B VERMONT B B NEW HAMP B B MAINE B B MASS B B CONN B B RHODE IS B B PENN N N NEW JERSEY B B W VIRGINIA N N MARYLAND N B DELAWARE N B VIRGINIA N B N CAROLINA N B S CAROLINA N B GEORGIA N B FL PNHDL N B FL PENIN N N AK N SLOPE N A AK ALEUTIAN A A AK WESTERN N N AK INT BSN B A AK S INT A A AK SO COAST A N AK PNHDL N A LEGEND TEMPS WITH RESPECT TO NORMAL PCPN WITH RESPECT TO MEDIAN A - ABOVE N - NEAR NORMAL A - ABOVE N - NEAR MEDIAN B - BELOW B - BELOW THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE. FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS PMDMRD. $$
     Maps Compliments of National Weather Service
powered by Cumulus v1.9.3 (1059)
Ambient Weather VWS v14.00
Top Website Map Copyright © 2007 - 2019 Foresthillweather.com Never base important decisions on this or any weather information obtained from the Internet