An Advanced Look at Winter Forecast 2010-11

As is customary for me, I try to provide an initial winter weather outlook around the first of September, just as we begin to think Fall. Why? It comes from my work experience in the private weather industry where critical planning for the upcoming winter takes place during September and October and that is when the winter outlook is so important. This includes the utility industry with regards to their planning on the amount of natural gas and heating oil will be required to heat our homes to local municipalities, state departments of transportation and the local snow plow operator and the amount of salt and anti-icing material may be required to keep our roadways clear of snow and ice and safe to commute on. This outlook is intended to assist everyone with these winter planning needs; however, it is a bit more generic. If you require a more specific winter forecast please feel free to contact me. I would be more than happy to accommodate you. Please note, depending on the request it may require additional resources that may require me to charge a minimal fee. But since this is one of my favorite things to do each year I will do my best to minimize any charges.

As is the case with the forecast for Autumn 2010, La Nina and a negative Pacific Decadal Oscillation will be the major dominating factors this winter. This will lead to above normal temperatures from the Northern Rockies into the Northern Plains/ Upper Midwest southeast and eastward. This includes the Great Lakes, Mid-Mississippi Valley, Ohio Valley, Tennessee Valley, Southeast, Mid-Atlantic and New England. The warmest temperatures, compared to normal, are likely to occur across the northern tier of the nation, especially in the Northern Rockies, Upper Midwest and New England.

Snowfall is likely to be near to a bit above normal along and north of the I-70 corridor. A bit more specific snowfall forecast will be released later.

Now, similar to the Fall Forecast, the Climate Prediction Center forecast for December, January, and February doesn't match up with my forecast. Instead, their prediction is for above normal conditions along the southern tier of the U.S. from southern California to the Southeast with the Northwest, Northern Rockies and Upper Plains below normal.

Here are some specifics:

December 2010

Chicago: 1.2 Degrees Above Normal, 12.8" Snowfall (4.1" Above Normal)

St. Louis: 2.2 Degrees Below Normal, 9.6" Snowfall (5.5" Above Normal)

Cincinnati: 2.6 Degrees Above Normal, 2.2" Snowfall (1.5" Below Normal)

Minneapolis: Near Normal Temperatures, 4.6" Snowfall (5.5" Below Normal)

Washington DC: 0.8 Degrees Above Normal, 3.2" Snowfall (1.7" Above Normal)

New York: 1.2 Degrees Above Normal, 5.5" Snowfall (2.9" Above Normal)

Boston: 1.0 Degree Above Normal, 6.0" Snowfall (1.6" Below Normal)

Denver: 1.7 Degrees Above Normal, 14.5" Snowfall (5.8" Above Normal)

January 2011

Chicago: 0.8 Degrees Above Normal, 15.2" Snowfall (3.9" Above Normal)

St. Louis: 1.1 Degrees Below Normal, 8.0" Snowfall (2.7" Above Normal)

Cincinnati: 2.8 Degrees Above Normal, 6.6" Snowfall (0.6" Below Normal)

Minneapolis: 1.3 Degrees Below Normal, 13.5" Snowfall (0.2" Below Normal)

Washington DC: 1.6 Degrees Above Nor0mal, 7.4" Snowfall (1.2" Above Normal)

New York: 0.7 Degrees Above Normal, 9.8" Snowfall (1.7" Above Normal)

Boston: 0.9 Degree Below Normal, 19.4" Snowfall (6.6" Above Normal)

Denver: 2.3 Degrees Above Normal, 6.3" Snowfall (1.4" Below Normal)

February 2011

Chicago: 1.2 Degrees Above Normal, 9.2" Snowfall (0.9" Above Normal)

St. Louis: 1.5 Degrees Above Normal, 4.9" Snowfall (0.3" Below Normal)

Cincinnati: 3.4 Degrees Above Normal, 2.8" Snowfall (2.6" Below Normal)

Minneapolis: 3.1 Degrees Above Normal, 3.8" Snowfall (4.4" Below Normal)

Washington DC: 0.7 Degrees Above Nor0mal, 3.7" Snowfall (1.5" Below Normal)

New York: 0.5 Degrees Above Normal, 5.8" Snowfall (1.8" Below Normal)

Boston: Near Normal, 14.0" Snowfall (2.5" Above Normal)

Denver: 2.3 Degrees Above Normal, 6.0" Snowfall (0.3" Below Normal)

A Look At Fall 2010

Warm Times Continue

Last year at this time when I was putting together the fall and preliminary winter outlooks I was seeing an El Nino amidst a cold PDO (Pacific Decadal Oscillation) facing me. That helped to lead to a very chilly winter for much of the eastern U.S. and especially the Southeast. This year the pendulum is swinging in the opposite direction and that means a La Nina amidst a cold PDO. So can we expect opposite conditions for this fall/winter? It is appearing so even though the U.S. long range seasonal forecast model (CFS) is predicting otherwise.

The latest run of the National Weather Service’s Climate Prediction Center’s seasonal forecast is indicating a cool Fall across much of the eastern U.S. with the coolest being centered over the Mississippi Valley.

This is an interesting forecast that is going against the analog years I have reviewed. I have looked at similar year’s in which we have swung from an El Nino to a La Nina during the summer months and a cold PDO was present. This has provided me with the following years: 1998, 1987, 1973 and 1963. These analog years taken just by themselves and composited provide the following:

Notice the marked difference in the image versus the CFS forecast. The composite would indicate temperatures running above to much above normal for the Mid and Upper Mississippi Valleys, the Plains and into the Rockies. In addition, warmer than normal conditions would also be likely to persist to the Atlantic Coast. It does hint at some cooler than normal conditions being possible in California. I actually think the cooler than normal conditions make extend a bit further north all along the Pacific Coast. Overall, this image fits pretty well into my thinking for this fall. So if you were hoping for the cool, refreshing feel of the season you may be saddened.

One of the most wonderful features of the season is the art show Mother Nature provides through the changing of colors the leaves and foliage. Can we expect a colorful season or somewhat more of a blah one? Unfortunately it is not looking real promising from the Tennessee Valley through the Smokies and along the eastern seaboard. . Not only has it been quite hot this summer but it has also been dry for these locations. Through June/July, some locations in these areas were more than 3” below normal.

The combination of heat and dryness has already begun to create some strain on trees in the Tennessee Valley and some leaves are already changing to browns and yellows and falling. The forecast for precipitation over the next 30 to 45 days, which will lead into the traditional change over season, will be at best, near normal; however, I anticipate much of the area remaining dry, especially for the Tennessee/Ohio Valleys and Mid-Atlantic. Best fall color this year will likely be across the Rockies and through the Great Lakes where average to above average precipitation has occurred. The peak of color may be a bit slower to arrive, though, due to the predicted above normal temperatures. I would anticipate about 1 to 2 weeks later than the normal depicted in the map below.

Here are some specifics for a few key locations for this fall season:

SEPTEMBER 2010

CITY-Monthly Average Temp-Departure from Normal-Monthly Snowfall-Snowfall Departure
Chicago, IL_66.4_+2.6_NA_NA
St. Louis, MO_71.4_+1.2_NA_NA
Cincinnati, OH_70.8_+2.3_NA_NA
Minneapolis, MN_62.9_+1.3_NA_NA
Washington DC_72.9_+2.4_NA_NA
New York, NY_68.6_+1.1_NA_NA
Boston, MA_64.9_+0.2_NA_NA
Denver, CO_64.3_+1.9_NA_NA

OCTOBER 2010

CITY-Monthly Average Temp-Departure from Normal-Monthly Snowfall-Snowfall Departure
Chicago, IL_58.1_+6.0_NA_NA
St. Louis, MO_59.6_+0.9_NA_NA
Cincinnati, OH_55.9_-0.6_NA_NA
Minneapolis, MN_50.7_+1.1_0.3”_-0.3”
Washington DC_59.9_+1.1_NA_NA
New York, NY_58.1_+1.5_NA_NA
Boston, MA_55.7_+1.6_NA_NA
Denver, CO_52.5_+1.5_0.9”_-3.2”

NOVEMBER 2010

CITY-Monthly Average Temp-Departure from Normal-Monthly Snowfall-Snowfall Departure
Chicago, IL_42.8_+3.5_0.9”_-0.9”
St. Louis, MO_47.6_+2.2_0.4”_-1.4”
Cincinnati, OH_47.0_+1.5_1.2”_-0.8"
Minneapolis, MN_35.6_+2.5_3.0”_-7.0”
Washington DC_49.9_+1.2_2.4”_+1.7”
New York, NY_48.0_+0.9_1.9”_+1.5”
Boston, MA_45.1_+0.2_2.2”_+0.9”
Denver, CO_39.8_+2.3_7.9”_-2.8”

Now, I know it is still August but it is never to0 soon to begin to look past the heat of summer to the wonderful chill of winter (now you know my favorite season). I have done just that and am ready to release my preliminary winter 2010 forecast. I will do this by September 1, 2010 so make sure to check back!

Revised "Doppler" Dale 2010 Hurricane Forecast

I have started digging into the Fall 2010 and even Winter 2010 outlooks and in the process have seen some changes in the way the tropics are looking. In addition, a few new reference years are being utilized for this forecast; of them, only 1998 was used in the previous forecast. The other years include 1987 and 1973. For this reason, I am revising this year’s tropical forecast to REDUCE the number of expected named storms from 14 to 10. I am also reducing the number of expected hurricanes from 9 to 7 with only two of these forecast to reach “Major” status, category 3 or higher. Storms making a U.S. landfall stayed unchanged at 3.

Will "Danielle" Be Born?

The remnants of once Tropical Depression 5 have made their way back over the northern Gulf of Mexico. The center of circulation was located south of the Pensacola, Florida, Monday afternoon, and was drifting west.

As of 2:30 PM CT, the eastern side of the low had minimal cloud cover with the western side seeing quite a bit of convection. Enhanced convective development had eased through much of

the morning hours but during the last hour or so has begun once again. Air Force reconnaissance aircraft were flying the storm and had located several locations on the relatively convective free eastern side with winds of 20 to 25 mph. As of this post, they had not flown on the convectively filled western side.

I already believe the system is again a tropical depression and I would expect the National Hurricane Center to officially classify it as such by this evening. The disturbed weather will continue to find itself in a favorable environment this evening and into Tuesday as it continues to drift to the west and then northwest. This should allow the system to further develop and

organize and I anticipate it will reach close to Tropical Storm strength, becoming Danielle if it does, before making landfall Tuesday evening in southeast Louisiana. The Storm Force 31

computer forecast, BAMS, continues to indicate that Tropical Storm Danielle remains a strong

potential. It forecasts the winds of the system to reach Tropical Storm strength, minimum of 39 mph, by late tonight.

By midday Tuesday, it forecasts the system to be at its peak just prior to making landfall and continuing on a track to the northwest. This track would take the center of the system near to New Orleans.

The BAMS, is outside the consensus of most of the models by developing the system into a well organized tropical storm. The majority of the computer forecasts are forecasting a depression with near tropical storm strength or at worst a minimal tropical storm.

Either way, the energy of the system appears it will track into southeast Louisiana on Tuesday and then begin to make a turn to the north through the middle of the week. It will eventually drift towards the northeast through northern Mississippi and the Tennessee Valley this weekend meaning another unsettled weekend is likely.

TD5 MAY GET SECOND SHOT TO BECOME “DANIELLE”

The remnants of what was earlier last week TD 5 are drifting back towards the Gulf of Mexico. Sunday, the low pressure circulation will move out of southeast Alabama and cross through the panhandle of Florida. By early Monday, it will once again be over the warm waters of the Gulf of Mexico. It will also begin to find itself back in a favorable environment for development into a tropical system. I anticipate by Monday afternoon, it will again be classified as a tropical depression. Depending on its precise track, it could strengthen into a tropical storm on Tuesday. This strongly depends on a more southerly track, one that keeps it over the warm waters and further away from the coast where it would encounter some frictional shear.

Guidance on Saturday had been trending a bit further north, regarding its track, versus Friday's runs; however, the first look at the Sunday guidance is back just south of the Coast. One model that has been consistent over the past 48 hours is the Storm Force 31 BAMS model. It continues to track the low south of the Coast from near Destin west to northeast Texas by Wednesday.

On Friday, it was forecasting the system to intensify into a hurricane by Tuesday and Saturday evening's late run continued this trend. Additionally, it was forecasting the system to strengthen into a strong category 1 to a lower end category two hurricane by midday Wednesday.

I am not sure if it will have enough time and enough going for it to completely strengthen that much but I would not be surprised to see it become Tropical Storm Danielle.

Remnants of TD 5 Going Loop-De-Loop

May Become Tropical Again?

The remnant low of what was once tropical depression 5 was meandering through southern Mississippi Friday evening. It has sent a spoke of energy across the Tennessee Valley and that help to spawn afternoon showers and thunderstorms with tropical downpours. On Saturday, it will drift to near Montgomery, Alabama and that will bring it into close proximity to the Valley to once again deliver more widespread scattered convection, especially for the southeastern half of the region from Hamilton-Decatur-Huntsville-Winchester southeastward. Locations in this zone will see afternoon rain chances in the “likely” category with precipitation chances at or above 50%.

While northwest of this line rain chances will be less and more scattered. In fact, some in northwest Alabama and Wayne and Lawrence County in Tennessee may not see any rain at all. For this reason, afternoon high temperatures will very by as much as 10 degrees from Ft. Payne to the Shoals, Saturday.



The remnant low will drift into southeast Alabama/southwest Georgia on Sunday and that will take the best rain chances to the east and south of the Valley; however, widely scattered activity is still likely for Marshall, Jackon and DeKalb Counties. The heat will again begin spreading east and by Monday as the low drifts into northwest Florida/northeast Gulf of Mexico, highs will again reach into the upper 90s and possibly top near 100 degrees again. It will also be quite humid meaning Monday will be just plain “HUMISERABLE” and heat index values will likely climb to near 110 degrees again.

As the low drifts back over the warm Gulf of Mexico, it will find itself back in an environment favorable for redevelopment and strengthening. The low may once again become a depression by Monday and strengthen even further into a potentially named tropical system by reaching tropical storm strength by early Tuesday. The low will likely drift westward as a light easterly flow around and upper level high pressure system drives its motion. By Tuesday, it will likely be tracking near the Louisianna Gulf Coast and may continue to strengthen. The Storm Force 31 in-house computer forecast model (BAMS) is indicating the possible strengthening of the low to a HURRICANE by midday Tuesday.

The system will then likely drift towards the northeastern/eastern Texas coast by Wednesday into Thursday. If you have plans along the Gulf Coast this weak it is advised that you remain weather aware regarding this system.

Tropical Depression Weakens & Is No Longer

Reorganization and Strengthening No Longer Likely

Latest observations from buoys, satellite and reconnaissance aircraft indicate that Tropical Depression Five has faded and no longer is a depression.

Officially, the latest information concerning the depression, as of 4pm CT:

Location: 28.3 N 87.6 W or about 170 miles south of Mobile, Alabama
Maximum Winds: 30 MPH
Movement: NW at 12 MPH
Pressure: 29.80”

The tropical storm warnings that were in effect for the Gulf Coast have been lifted and are no longer in effect.

The remnants of the depression will continue to lift off to the northwest through the remainder of this evening and tonight and will move onshore near Bay St. Louis during the morning hours on Thursday and continue to slowly drift north through Mississippi into Friday before turning more northeasterly through the weekend.

This track will allow deep, gulf moisture to lift northward into Alabama and this will lead to an increase in scattered showers and storms this weekend. Where the rains fall, some cooling relief from the heat will be felt. Where they don’t, it will be just “humiserably” hot.

TD 5 May Become Tropical Storm Danielle

Track Dependent; Relief May Be Delivered to the Valley

As of 10 AM CT, Wednesday, tropical depression five had a large circulation pattern but remained overall disorganized over the eastern Gulf of Mexico. Scattered showers and storms are occurring from the Louisiana coast to southwest Florida.

The center of the depression was located at 27.8N, 86.8W or about 190 miles south of Pensacola, Florida. Minimum central pressure was 29.77” and the maximum sustained winds were 30 MPH.

Due to the broad nature of the circulation, exact track of the system is tough to discern; however, it appears to generally be drifting northwest at about 12 MPH.

Tropical Storm Warnings are currently in effect from Destin, Florida to Intracoastal City, Louisiana. A tropical storm warning means that tropical storm force winds are expected somewhere within the warning area within 36 hours.

As TD 5 continues to drift to the northwest through Thursday, it will encounter a more favorable atmospheric wind pattern. This will aid in allowing the system to better organize. However, the broad circulation will act as an inhibiting factor and as a result it is likely the system will be slow to strengthen and may actually struggle to ever reach tropical storm strength.

This is also being indicated by multiple computer guidance forecasts. Several of these actually forecast the depression to remain a depression through the next five days while a few others intensify it to minimal tropical storm force strength. Only a couple of the forecasts predict the system to intensify to near hurricane strength and/or indicate rapid strengthening. The Storm Force 31 forecast model also forecasts slow strengthening and maintains the depression as a depression through its life cycle.

Regarding the track of the system, a likely continuation of a northwestward drift is expected. This will likely allow the system to move onshore along the Mississippi coast Thursday morning. This is supported by the majority of the computer forecasts and the official National Hurricane Center Forecast. The Storm Force 31 model is a bit east and south of the center of the official track; drifting the center of the system towards Montgomery, Alabama by midday Sunday.

The official track would be a favorable one for the Tennessee Valley in that it would help bring some potential relief from the heat. This would be due to the increased coverage area of likely showers and t-storms. This too, would be beneficial for the Valley as the portions of the Valley are experiencing abnormally dry conditions.