Monday, March 14, 2011

March 14 2011 Forecast Discussion

FORECAST DISCUSSION
Image above is 24 hour 18z GFS Ensembles.
Low pressure system located over Tennessee with strength of 1014 mb makes for a weak SLP (Surface Low Pressure). We will be seeing this air mass wrapping around a mass of pure Gulf air on the right side of this low. With tight isobars surrounding the low, winds are expected to be fairly strong.
These winds should be able to bring a decent warmup to the Southeast as a whole, as the warm air also extends a bit north of this SLP.
Main issue is the cool air mass behind this low pressure system.
The cool air mass has likely been taken from the Arctic masses, and although a somewhat cool air mass continues to support this air mass behind the low, the cool air mass does not seem to be strong enough to provide any strong thunderstorms.
The cool air mass will be supported by a high pressure area, but the cool air mass should subside as the low continues off.
The other possibility is the high moving southward, taking on warm air as the cold air mass retreats.
While a line of rain and embedded storms is likely, the weakness of the low and the only relatively cool air mass on the backside of this low will prohibit severe storms from developing.
However, any storms that do develop will have a risk for some gusty winds.

Elsewhere, SLP over the Rockies should be the same strength as the Southeast low pressure system. This storm, however, will be different. The SLP will be pulling dry, warm air up from the Arizona area. The low will be shooting straight into a relatively neutral air mass.
Precipitation is expected to develop ahead of this low, but with abundance of dry air in the warmer air mass, I don't believe precipitation would be much of an issue. The precipitation would also be in the form of rain.
Main concern with this specific SLP will be how this low should move eastward and bring a strong push of warm air into the Midwest, Northeast.
The dry air should be overcome with humid air.
I would certainly not be surprised to see dew points and RH (Relative Humidity) measurements to greatly increase over the Midwest and Northeast.

That's about it. A new Forecast Discussion will be issued tomorrow.

BREAKING NEWS: USGS revises Japan Earthquake Magnitude to 9.0

The USGS has revised the Japan Earthquake to 9.0 instead of 8.9, a short time after the Japanese Agency also upgraded the magnitude to 9.0

US Weather Extremes: Top 10 Least Rainy Cities

10 least rainy cities
Number of days per year with rain
1. Yuma, Arizona
17
2. Las Vegas, Nevada
26
3. Bishop, California
29
4. Santa Barbara, California
30
5. Long Beach, California
32
6. Los Angeles, California
35
7. Great Falls, Montana
35
8. Phoenix, Arizona
36
9. Bakersfield, California
37
10. San Diego, California
42

US Weather Extremes: Top 10 Rainiest Cities

10 rainiest cities
Number of days per year with rain
1. Hilo, Hawaii
277
2. Quillayute, Washington
210
3. Astoria, Oregon
191
4. Elkins, West Virginia
171
5. Syracuse, New York
171
6. Buffalo, New York
169
7. Marquette, Michigan
168
8. Sault Ste Marie, Michigan
166
9. Erie, Pennsylvania
165
10. Binghamton, New York
162

US Weather Extremes: Top 10 Driest Cities

10 least humid cities
Avg relative humidity in %
1. Las Vegas, Nevada
30.5
2. Phoenix, Arizona
37.0
3. Yuma, Arizona
38.0
4. Tucson, Arizona
39.0
5. El Paso, Texas
42.5
6. Albuquerque, New Mexico
44.5
7. Winslow, Arizona
46.0
8. Grand Junction, Colorado
48.0
9. Winnemucca, Nevada
48.5
10. Reno, Nevada
50.5

US Weather Extremes: Top 10 Most Humid Cities

10 most humid cities
Avg relative humidity in %
1. Quillayute, Washington
83.0
2. Olympia, Washington
78.0
3. Port Arthur, Texas
77.5
4. Lake Charles, Louisiana
77.0
5. Apalachicola, Florida
76.5
6. Gainesville, Florida
76.5
7. Corpus Christi, Texas
76.0
8. Eugene, Oregon
75.5
9. New Orleans, Louisiana
75.5
10. Houston, Texas
75.0

US Weather Extremes: Top 10 Cloudiest Cities

10 cloudiest cities
Avg number of cloudy days per year
1. Astoria, Oregon
240
2. Quillayute, Washington
240
3. Olympia, Washington
229
4. Seattle, Washington
227
5. Portland, Oregon
223
6. Kalispell, Montana
213
7. Binghamton, New York
212
8. Beckley, West Virginia
211
9. Elkins, West Virginia
211
10. Eugene, Oregon
209

US Weather Extremes: Top 10 Sunniest Cities

10 sunniest cities
Annual percent of possible sunshine
1. Yuma, Arizona
90%
2. Las Vegas, Nevada
85%
3. Phoenix, Arizona
85%
4. Tucson, Arizona
85%
5. El Paso, Texas
83%
6. Flagstaff, Arizona
79%
7. Fresno, California
79%
8. Reno, Nevada
79%
9. Sacramento, California
78%
10. Albuquerque, N.M.
76%