Archive for September, 2007

Harvest Moon
September 26, 2007

The following email from Spaceweather.com showed up in my mailbox this morning, providing a nice concise explanation of why we call it the “Harvest Moon”:

HARVEST MOON: There’s a full Moon tonight (Wed., Sept. 26) and it has a special name–the “Harvest Moon,” the full Moon closest to the autumnal equinox. In the days before electric lights, farmers relied on moonlight to help them gather ripening autumn crops. The bright Harvest Moon allowed their work to continue late into the night. Now, post-Edison, we appreciate the Harvest Moon more for its beauty than its utility. Moonrise happens tonight at sunset; look east and enjoy the view!

Tom Tasselmyer

Growing Need For Rain
September 24, 2007

Though not severe around Baltimore, the drought continues.

September rain so far totals only .35 inches, 2.76 inches below the 30 year average.

The 2007 precipitation total is 23.57 inches, 7.87 inches below the 30 year average.

The weather pattern in the near term is not a particularly wet one but a cold front may generate scattered showers and thunderstorms on Thursday.

Remnants from a tropical weather system would be a blessing at this stage but the hurricane season has not thrown anything significant our way so far. There is tropical activity in the Atlantic and Caribbean so it is just a “wait and see’ situation.

John Collins

Tropical Potential
September 24, 2007

Tropical Depression #10 never did reach tropical storm status and the next name in line, Jerry, remained unused. The disturbance moved on shore Friday between Pensacola, Florida as a squally storm with bands of strong thunderstorms. Rainfall totals were generally less than 3 inches. Tornado activity was reported.

A tropical disturbance out in the middle of the Atlantic Ocean picked up the name Jerry on Sunday Morning. Jerry was initially tagged a “sub tropical storm” because the storm had not yet developed a “warm core” that is at the heart of tropical cyclones. Jerry was declared a full tropical storm Sunday night and is expected to stay out to sea, a danger only to shipping interests. (Monday update…Jerry downgraded to tropical depression)

Three other tropical features are being tracked. Two in the Atlantic are tropical waves that have some potential for development. A storm cluster over the Yucatan of Mexico is expected to move out over the southern Gulf of Mexico(Monday update…disturbance now in SW Gulf) where warm waters may help the storm develop into a tropical disturbance. The coming week may get interesting.

John Collins

Just About Jerry
September 21, 2007


Low pressure 100 miles south of Apalachicola early Friday morning was doing its best to become the 10th named storm of the hurricane season, but as of the 5:30am update the National Hurricane Center reported the storm was not yet fully tropical. Still, areas around the gulf coast of Florida have been dealing with severe thunderstorms throughout the early morning with reports of possible tornadoes in Lake County in north central Florida and Franklin County on the Florida panhandle near Apalachicola. The severe weather is never welcome, but the showers are actually good news for this part of the country. Apalachicola is 17.74″ below normal precipitation for the year. Buoys in the gulf are reporting wind gusts to 30 mph with 8 foot waves. Conditions appear favorable for this storm to continue to intensify as it tracks northwest toward the Mississippi and Louisiana coastline.

Tom Tasselmyer

Typhoon Wipha
September 18, 2007

Tropical cyclones are active in the Pacific. Typhoon Wipha is about to strike the China coast.


Wipha has been downgraded from a “super typhoon” to simply a “typhoon”. Nonetheless it is a powerful storm and will be one of the strongest to hit China in years.

John Collins

Hurricane Floyd Anniversary
September 16, 2007

September 16 is the anniversary of Hurricane Floyd hitting the Mid Atlantic region.

The storm formed out in the Atlantic and at its’ peak was a category 3 storm with winds to 125 mph.


Floyd turned to the north before reaching Florida and headed for the Carolina coast. Floyd was a category 2 storm when it crossed Cape Fear, NC and weakend to tropical storm strength when the center of the storm passed just east of Ocean City.

14 to 15 inches of rain fell in Cecil and Kent counties.

11.6 inches of rain was measured at Annapolis.

8.62 inches of rain was recorded at Ft. McHenry.

The rain total on TV Hill was 5.96 inches.

The 5.02 inches of rain recorded at BWI-Marshall Airport stands as the record for the date.

4.44 inches of rain was recorded at the Maryland Science Center.

The peak wind gust on TV Hill was 62mph and the peak at the airport was 43mph

The Mid Atlantic region was experiencing a drought before Floyd arrived. The storm’s rains made September 1999 the second wettest on record and broke the drought.

John Collins

Weekend Tropical Activity
September 16, 2007

September and early October are the peak times for tropical weather activity in the Atlantic, Caribbean and Gulf of Mexico.

The most recent named storm is still active in the Atlantic. Ingrid is a tropical depression and is having trouble staying organized because of upper level winds. Those winds have been responsible for keep the storm from developing into a hurricane. Ingrid continues to drift to the northwest and is expected to weaken.

The circled area labeled #1 in the picture above has some potential for slow development and is being watched.

The area labeled #2 is associated with an upper level low and there is no apparent surface circulation at this time.

John Collins

Humberto Leftovers
September 16, 2007

Remnants of Hurricane Humberto passed over the Mid Atlantic region late friday and early saturday. The area received some much needed rain but not enough to significantly affect the drought.

As of saturday (September 15) Baltimore stands at 1.69″ short on precipitation for the month and 6.80″ short for the year.

Parts of the Eastern Shore received to most generous rainfall from friday night’s storm passage. American Corner received 1.17″ but a little farther to the north, Elkton received only .22″ of rain.

On TV Hill only .18″ of rain fell. Officially BWI-Marshall received only .14″ from the storm.

John Collins

Chilling Down
September 16, 2007

Autumn officially arrives next Sunday but temperatures are taking an unseasonal dip this weekend. The average high this time of year is 78, and the low 57.

For the next couple of days high temperatures will be running about 10 degrees below average and lows are expected to get close to record values.

The Sunday morning record low is 41, set back in 1873. The airport temperature is not likely to get quite that chilly but could get within 5 degrees of the mark.

The Monday morning record low is 44, set back in 1984 and is vulnerable.

John Collins

Ingrid, 9th Named Storm of 2007
September 14, 2007


Late Thursday evening a NOAA hurricane hunter plane found just enough wind and circulation in the tropical depression 840 miles east of the Caribbean to upgrade the depression to tropical storm status. With maximum sustained winds of just 40 mph it’s really just a cluster of strong thunderstorms, but 40 is the magic number when naming storms so it’s “Hello Ingrid!” The official forecast from the National Hurricane Center keeps Ingrid as a fairly weak tropical storm due to some wind shear in the area preventing further strengthening. The expected track takes Ingrid west/northwest to a position north of the Virgin Islands early next week.

Tom Tasselmyer