Weather! Tomas lashes Haiti; cool weather, but improving this weekend

Reminder: Daylight Saving Time ends at 2am on Sunday morning; don’t forget to set your clocks back Saturday evening, or risk showing up an hour early to everything Sunday morning. Please check the batteries in your smoke detectors, too. Tomas has returned to hurricane status, just in time to make landfall in southwestern Haiti. I’m […]

November 5, 2010; 2:06 PM • by Weather Dan

Reminder: Daylight Saving Time ends at 2am on Sunday morning; don’t forget to set your clocks back Saturday evening, or risk showing up an hour early to everything Sunday morning. Please check the batteries in your smoke detectors, too.

Tomas has returned to hurricane status, just in time to make landfall in southwestern Haiti.

I’m just going to let the pictures speak for themselves.

Boston.com’s The Big Picture blog has a great set of photos taken ten months after the earthquake. With so many people still living in tents, the winds, flooding rains, and landslides will all be a threat to the people’s continued survival. The rains will do little to nothing to help the current cholera outbreak, either. The road to recovery for this nation is neither short nor smooth.

On a somewhat lighter note, here’s a quick lesson why not to believe everything that you see, even when it comes to weather. This is the 9:40pm observation from the Automated Weather Observing System (AWOS) unit at the Blacksburg/Mongtomery County Executive Airport (KBCB):

METAR KBCB 050140Z AUTO 29005KT 10SM VCTS CLR 04/02 A2961 RMK AO2 LTG DSNT NW

For those of you not versed in decoding METAR, I’ll go over this. There are a couple interesting observations here.
After METAR, the airport identifier, the time/date and source of observations, we have the wind direction (290 degrees) and speed (05 knots), and visibility (10 statute miles), and a remark about the current weather – VCTS, which is code for thunderstorms in the vicinity of the site.

Thunderstorms? Last night? Most of you who either were at the game or watching on TV could tell that last night it was cold, with temperatures in the upper 30s and partly cloudy skies. In fact, the observation above confirms this – the only cloudcover notation is CLR, or clear skies, and the temperature and dewpoint are listed as 04 and 02 degrees Celsius, respectively. (This converts to about 39 and 35 degrees Fahrenheit.) Then at the end we have some remarks (RMK) or comments about the current weather, talking about lightning in the distant northwest.

How could we have lightning and thunderstorms in the vicinity with clear skies and a temperature that doesn’t normally support convective development? If you guessed fireworks and pyrotechnics, you guessed correctly. The observing site is about a mile south-southeast of Lane Stadium, and both the light and sound from the fireworks could be easily heard and seen from the airport.

The area of low pressure that brought 0.80” of rain Thursday is over New England now, and an area of drier air has moved in behind the front that cleared the area last night. Drier air means fewer clouds, and that’s what we’re seeing over the region this afternoon. For the rest of Friday, highs will reach near 60, before dropping into the upper 30s tonight.

Another disturbance is set to cross the area on Saturday, bringing back the chance of some scattered showers during the day on Saturday. Any new rainfall should be pretty small, with accumulations topping out around a tenth of an inch. Highs will climb into the mid 50s, with overnight lows into the mid 30s.

SpiderCast (vs. James Madison, 3:30pm): There’s a small chance of a shower Saturday afternoon; otherwise, plan on partly to mostly cloudy skies, with kickoff temperatures in the mid 50s, dropping into the upper 40s by game’s end.

On Sunday, we’ll see some improvement in sky cover as the clouds break up. Temperatures will be similar to Saturday, with afternoon highs in the mid 50s and overnight lows in the mid 30s.

I’m looking at the possibility of a warming trend early next week, with temperatures climbing into the 60s (and closer to the average for this time of year). I’ll have my next update Monday.

November 5, 2010 2:06 PM 0