I've had a number of people ask me about the chance of snow on Wednesday. It seems that some forecasters, using the data from one model, have been touting the possibility of snow on Wednesday for southeast Texas.
Here is the real scoop on the outlook for this week.
The week, overall is likely to be on the cloudy, wet side with somewhat chilly temperatures. There will be a chance for some thunderstorms late Monday as a cold front moves through. There should be another opportunity for precipitation on Wednesday and Thursday as moisture from the Pacific overrides cold air on the ground and an upper-level trough heads east. This feature may be supported by a surface low in the northwest Gulf of Mexico. Temperatures will be on the chilly side from Tuesday through Thursday with lows in the 30's and high temperatures from the upper-40's to near 50.
So what about our snow chances?
Generally there have to be three basic conditions for snow to fall. Temperatures on the ground must be cold enough to keep any snow from melting before it reaches the surface. Temperatures do not have to be below freezing, but roughly they have to be at least 40 degrees or colder. Even more important temperatures in the upper-atmosphere, where clouds form have to be quite cold, ranging from 5 degrees or lower for one kind of snow and -4 to -13 degrees for another type of snow. And, finally, there must be enough moisture available aloft for precipitation to actually form and fall.
So looking at the Wednesday and Thursday time-line, here is what we see. Upper-level temperatures across large parts of Texas will be very close to the conditions necessary for snow to form. Likewise, temperatures on the ground will be close to being cold enough (at least late at night and early in the morning) to support some snow reaching the ground. And, it does look as though there will probably be sufficient moisture available.
Based on this, at least some snow or sleet might be possible, though not probable, over parts of southeast Texas with the best chances north and west of Galveston County. Certainly any accumulation seems unlikely. Most important, conditions for snow appear to be marginal at best. One highly utilized forecast model, the GFS (Global Forecast System) offers a slightly more favorable outlook on the chances for either snow or cold rain, while another widely used model, the ECMWF (European Center for Medium Range Forecasting) paints a somewhat drier scenario for this time frame. Needless to say, I wouldn't begin planning for any snowmen just yet.
In any case, coats, sweaters and rain-gear are likely to be very useful items to have for this coming week. As for the longer term, it appears as though Saturday will be rain-free, though we may need to wait a few days to find out if we will luck out again for the second weekend of Mardi Gras events.
Below are links to maps showing expected minimum and maximum temperatures for the middle of this week:
Our wet, windy weather has been slow to move out of the area, but prospects are still looking up for the weekend. With luck, those attending the Mardi Gras parades in Galveston may even see some sun on Saturday as drier air finally moves into the region behind our latest storm system.
Certainly, compared to the high tides, lingering rain and winds gusting to 46-mph in Galveston over the past 24-hours, the partly to mostly cloudy skies and temperatures in the 40's and 50's expected over the weekend should seem almost idyllic for weekend festivities.
Those wishing for a long spell of sunny weather are probably going to be disappointed. Another system may bring rain as early as late Sunday and much of next week could see a lingering threat of precipitation. In fact, we will probably need to continue to have luck to avoid rain during the the remainder of the Mardi Gras period. The latest forecasts are projecting chilly, wet weather though mid-February. However, given the good timing, weather-wise for this weekend, is it too much to ask for the same next weekend? I, for one, hope not!
Below is a link for the rain and temperature outlook for the coming 6-10 days:
A complex storm system involving an upper-level low pressure trough moving in from the west, a strong southern jet stream flow and a developing surface low pressure system near the Texas coast will combine to bring very windy conditions and the possibility of heavy rainfall to Galveston County on Wednesday and Thursday.
This combination of events will result in strong easterly winds and high swells along the upper-Texas coast. Tide levels may reach 2 to 2 1/2 feet above normal levels and could result in water levels of 3-4 feet during high tides. Off-shore areas may experience gale force winds Wednesday night and Thursday with sustained winds of 25-30 mph and gusts to 40-mph possible along the immediate coast.
On the plus side, the system should move east of our area Friday, giving us partly cloudy skies and chilly, but not frigid, temperatures for the first weekend of Mardi Gras celebrations.
Below are links to the Coastal Flood Watch and the rainfall outlook for the next few days:
It will come as no surprise to residents that this past month was the coldest January in 20 years.
The average temperature for the month in Galveston was 50.4 degrees, which is 5.4 degrees below normal. This makes it the coldest January on the Isle since January, 1985, with an observed monthly average of 48.1 degrees, slightly edging out January, 2001 which had a 50.5 degree mean.
The persistent chill also was felt on the mainland, where League City reported a 48.7 degree average temperature for the month, which is 4.7 degrees below normal at that location.
January, 2010 brought 5 days where the mercury dipped below freezing in Galveston, giving it greatest number of freezing days in a month since January, 1997 (which also saw five days with freezing temperatures). In League City 9 days, or nearly a third of the month, saw mornings where the temperature plunged to 32 degrees or lower.
This persistent cold was in keeping with the pattern seen in December, when temperatures averaged 5.2 degrees below normal in Galveston and 4.2 degrees below normal in League City.
By contrast, January was much drier than December locally with only 2.27" of rain recorded in Galveston (1.81" below normal) and 2.41" measured in League City.
If the long-term forecasts are correct, this colder than normal trend should continue through February along the Gulf Coast, though much of Texas will have temperatures close to normal (see link below):
With the first weekend of Mardi Gras looming, more than a few people are interested in how the weather will be this next Saturday and Sunday. The concern may be heightened by the fact that the coming week is likely to see more than a little rainfall.
Fortunately, current forecasts suggest that Mardi Gras revelers may be in luck. Although a couple of rain systems will move through the area in the coming week, they should be out of the picture by the time the weekend arrives. That will, most likely, result in partly cloudy skies and seasonably cool temperatures for Saturday and Sunday.
The first culprit in our projected parade of rain systems is a weak upper-level disturbance that should pass through Texas on Monday. This is not likely to be much of a rain maker, but may bring cloudiness and showers to the area. A much more potent system, with an upper-level low and a surface low developing the the Gulf of Mexico, could bring heavy rain to Galveston County late Wednesday or Thursday.
Based on current trends, however, this system should move out by Friday. This will leave northwest winds aloft over the region, leading to drier conditions and cool temperatures for the weekend. In other words, the weather should not inhibit anyone who wants to get into the Mardi Gras spirit and "let the good times roll"!
Below is a link to the five-day precipitation outlook and projected low and high temperatures as we move into the weekend:
I was talking to weather expert Steve Rubens last night about the current weather pattern. In particular, an especially strong southern jet stream that will bring rapid weather changes and wet, cool weather to Galveston over the coming weeks.
While it may not be obvious to many living here, distracted by recent episodes of dense fog and freezing temperatures, January has been quite dry in Galveston County. To date, Galveston has received only 1.11" of rain for the month, which is 2.49" below what could be expected. League City has been even drier with only 1.01" of rain for January.
That should change by early Friday as an upper-level storm system and approaching cold front bring the possibility of heavy rain to the area. Additionally, that may just be the beginning of a period of wet, changeable weather over southeast Texas.
With a stronger than normal southern branch of the jet stream (also called the "sub-tropical jet") in place, we can expect a period of rapid weather changes with storm systems racing from west to east across the southern half of the country. This is suggested in the long-term climate outlook, which projects a wet, cool February for southeast Texas.
Certainly the emerging pattern makes it appear as though February will merit the old adage: "If you don't like the weather, just wait a little while"
Below are links to sites providing the monthly weather outlook for February, the latest upper-level wind flow and jet stream map (at approximately 30,000 feet above sea level) and an article briefly explaining jet streams and weather:
The latest models are suggesting that the push of cold air due to reach the area by early Friday may not be quite as intense as previously projected. Even though temperatures are still expected to drop into the 30's on Saturday and Sunday, most or all of Galveston County will likely be spared freezing temperatures.
On the other hand, rain chances ahead and along the front continue to creep up. We could see a chance of showers as soon as early Thursday with thunderstorms likely early Friday. Skies should clear by the weekend with sunny, chilly weather still anticipated.
Below is a link to the five-day precipitation outlook:
A UTMB retiree, he produces a daily weather forecast for Galveston.com, offers courses on various aspects of climate through the Osher Lifelong Learning Institute at UTMB and serves as a lecturer for the Elder Hostel program at Texas A&M-Galveston.
Stan lives in Galveston with his wife, Margaret, who is a local artist, certified master gardener and master naturalist.
