A heat wave recap; generally quiet tropics
Last week's U.S. heat wave has finally subsided, and most of the Northeast will see some cool highs in the 70s today. Unfortunately, the Midwest, and mid-Atlantic will continue to see high temperatures in the 90s for the rest of this week, and the southern Plains will be forced to continue to endure triple-digits.
According to the National Climatic Data Center (NCDC), 2,100 daily high maximum temperature records have been set so far in July 2011, and 51% of those were set last week. 4,734 daily high minimum temperature records have been set so far this month, and 55% of those were set last week. Here's a breakdown of last week's records for the period July 18 through July 24:
High Maximum:
• 1,076 warmest maximum temperature for the date
• 90 warmest maximum temperature for the month of July
• 56 warmest maximum temperature of all time
High Minimum:
• 2,595 warmest minimum temperature for the date
• 207 warmest minimum temperature for the month of July
• 123 warmest minimum temperature of all time
The number of warm minimum temperatures is especially disturbing, as these tend to have more of an impact on health than the high maximums. When the temperature remains high at night, it prevents the body from being able to recover from the day's heat. According to NOAA, from July 1 through July 19, there were 22 heat-related deaths in the United States. Reuters is reporting that 34 deaths resulted from this heat wave. In an average year, heat remains the number one weather-related killer in this country. In some ways, the overnight low temperatures are the best way to quantify a heat wave, possibly even better than the heat index.
Figure 1. Map of daily high maximum temperature records for the period July 1 through July 25 from NCDC. Red circles without an X denote a broken record; red circles with an X denote a tied record.
Tropical Overview
The wave formerly known as Invest 90L
The wave formerly known as Invest 90L is moving slowly west through the Caribbean near Jamaica. A new burst of convection started this morning, which will undoubtedly produce some heavy rain over southern Cuba and Jamaica. While low-level circulation has remained about the same since late last week, the wave has become top-heavy with increased circulation at higher levels (700-500mb). None of the models (GFS, ECMWF, CMC, NGPS, UKMET) are developing this wave as tracks into the Gulf of Mexico, and they're all in agreement that the path will be toward far southern Texas or northern Mexico, except for the ECMWF deterministic run, which hints that it will take a turn toward the northern Gulf. However, this model hasn't shown actual development from the wave since Tuesday or Wednesday of last week.
NHC has dropped this invest as of Saturday afternoon, but it remains on their radar. They're giving the wave a 0% chance to form over the next 48 hours. Given the recent uptick in mid-level circulation, I'd imagine they're still a little concerned about the potential for this wave to fire-up again once it's in the Gulf, and it will surely be of concern for Cuba as it tracks westward. However, given the lack of model support for almost 7 days in a row now, I'd say this wave has seen its glory come and go.
Figure 2. Visible tropical Atlantic satellite captured at 11:14am EDT on Monday.
Other North Atlantic waves
There are a couple other waves to speak of that have left the coast of Africa in the past few days, one located near 40W and the other closer to Africa, around 30W, which is tangled up in the monsoon trough. The former is expected to take a southerly track, skirting northern South America, and possibly into the Bay of Campeche. Given this track, none of the models are suggesting it will develop. However, tropical cyclones that spin up in the Bay of Campeche generally have a short forecast lead time, so it's something to watch. The latter wave could take a slightly more northern track through the Caribbean islands, and a couple of the models seem to favor this wave for development at the end of their runs.
Tropical wave activity has been lacking so far this season, but climatologically we should see an increase in African easterly waves in August and September.
Angela
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 — Blog Index
very good analysis.
For everything except outdoor workers and possibly*farming, the overnight low is a better indicator of the degree of heat-related problems likely to arise than the daytime high.
The rate at which heat transfers between a heat source and a heat sink is proportional to the difference in temperature between the source and sink.
Buildings store heat during the day, and radiate&etc that stored heat during the night. A high overnight-low slows the rate at which a building can cool itself. And so during a heatwave, the building starts the next day warmer than the day before, and thus warms up faster (unless daytime temperature has decreased a lot).
Which increases heat stress upon folks who can't afford air conditioning, and increases the electricity bill for those who can.
That increased electricity bill derives from using more power, so electric companies have to produce more power to meet that demand, usually at a much higher price per kilowatt. The most expensive, the most inefficient, and the most polluting generator-plants are the ones fired up to produce peak-power when the demand peak greatly exceeds the average peak.
The extra pollution aggravates the medical problems brought on by heat stress. As well, it affects folks with other medical problems who can afford an air-conditioned lifestyle
The extra electricity being carried by powerlines heats up those powerlines to higher than normal temperatures. Which in turn increases the resistance of those powerlines to current flow. With more electrical power being wasted generating heat in those powerlines, even more generator-plants have to be called online.
Until eventually ya get to brownouts (when the voltage drops because of high demand, which causes an increased demand for current flow, which causes even more heating of the powerlines, which causes even more resistance to current flow within those powerlines, repeat...) and rolling blackouts (a decision to cut-off power to some sections of the grid to maintain a safe operating voltage on the rest of the grid) to prevent a total systems failure.
* Each plant enzyme has a specific temperature range in which it functions well. Exceed or fall beneath the ranges of those enzymes and the plant's metabolism goes into slowdown-to-shutdown mode. And unlike animals, most-approaching-all agriculturally-important plants have little means of controlling their internal temperatures.
Forgot the imagery... lol
...Wet conditions to persist across extreme southeast Louisiana
and coastal Mississippi through at least Friday...
A wet pattern will persist across southeast Louisiana and coastal
Mississippi through the week. Widespread showers and thunderstorms
are forecast to occur each day. With ample moisture in place...some
of these storms will be capable of producing brief periods of
locally heavy rainfall with rainfall rates as high as 2 to 3 inches
per hour.
Widespread flash flooding is not likely...so a Flash Flood Watch
is not warranted at this time. However...localized impacts such as
ponding of water on low lying roadways and in areas of poor drainage
can be expected in some areas each day. If conditions become more
favorable for widespread flash flooding...a Flash Flood Watch will
be issued at that time.
Most impacts will be minor...and will not pose a threat to life or
property assuming some caution is taken by the people in the
affected area. Most of these ponding impacts will be addressed
with Urban and Small Stream flood advisories. Flash flood warnings
will be issued if conditions appear to pose a significant threat
to life and property...such as homes or businesses likely to be
flooded...or closure of several roadways due to high water.
And, currently:
*atmo looks around for more fans to point NW*
Link
I know, everyone is entitled to their opinion. I just don't see this really getting going, UNLESS it misses or only skirts the Yucatan, in which case it may develop. It still has a long way to go and very little time before then.
.. Significant weather advisory for Hardin... Jasper... Newton...
Jefferson and Orange counties... significant weather advisory for
Calcasieu Parish until 530 PM CDT...
At 429 PM CDT... National Weather Service meteorologists detected a
line of strong thunderstorms from 12 miles southwest of Lumberton to
6 miles south of Deweyville... moving south at 10 mph.
* The line of strong thunderstorms will be near...
Hartburg...
Mauriceville and Forest Heights...
Bevil Oaks and Pine Forest...
Vidor by...
Rose City and Beaumont...
These storms could produce rainfall amounts of one to two inches in a
short period of time... resulting in ponding of water around low lying
roadways. Remember... do not drive your vehicle into water covered
roadways.
Lat... Lon 3021 9438 3031 9373 3008 9366 3000 9427
850mb vorticity becoming better defined!
Getting that cyclone symmetrical look imo.
1800 UTC
2100 UTC
Emergency workers block Fish Hatchery Road in Lacombe Monday, July 25, 2011, after run-off from heavy rains swept away a large culvert under the road, leaving the asphalt unsupported. A crew used heavy equipment to retrieve the culvert and place it on the bank. Traffic south of the break was diverted onto Pontchartrain Drive.
thanks!
Not really sure how land could help a tropical system which fundamentally requires warm water to develop. And quite the opposite, actually, strong storms don't feel land so much whereas weaker ones tend to be damaged badly. For example, Bonnie last year was forecast to reach around 50-55mph before it reached Louisiana last July, but the passing over Florida killed it.
Can you believe all of the rains missed me to the southwest! Lol. It's especially mean because I can hear it. Well I'm glad you got some rain. :)
Sorry. I mean hurricane Don. It doesnt have the time.
I think it would be safe to say that whatever mid-level circulation we are following is at least trying to work down to the surface. 850 mb. vorticity has increased over the past few hours, a sign that something is trying to work its way down.
6 hours ago:
Now:
Ahh, I thought she'd put her name on it. Threw me. Thanks.
Thanks!!!
But, at the same time, it would have little more than a day before it reached the Mexico/Texas coastline, which after a land passage is not likely to be enough time to develop. It's jmo, I could be wrong.
That's not true. As the case with 90L, if it were to go over land at this present time, how would land disrupt it more so than a hurricane with a well-defined circulation? As was the case with Bonnie, while not as developed as hurricanes, its circulation was well-defined, and land disrupted it severely.
She did.
Viewing: 601 - 651
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 — Blog Index