[image-156][image-172][image-188]NASA Sees Remnants of Tropical Storm Boris Merging with Gulf Low
The remnants of former Tropical Storm Boris moved over southern Mexico and NASA and NOAA satellite data showed that they were merging with a low pressure area in the southwestern Gulf of Mexico. In addition, data from NASA's TRMM satellite was used to compile rainfall totals from Boris' slow trek over southern Mexico.
A visible image taken from NOAA's GOES-East satellite on June 5 at 10:45 a.m. EDT showed the clouds associated with developing System 90L in the Bay of Campeche merging with the remnants of former Tropical Storm Boris.
When NASA's Aqua satellite passed over the remnants of Tropical Storm Boris on June 5 at 08:05 UTC (4:05 a.m. EDT), they were merging with System 90L, the elongated low pressure area in the southwestern Gulf of Mexico. The Atmospheric Infrared Sounder (AIRS) instrument aboard Aqua provided temperature data on the clouds associated with both Boris' remnants and System 90L Both low pressure areas showed high clouds with temperatures near -63F (-52C). Cloud top temperatures that cold indicate thunderstorms strong enough with the potential to drop heavy rainfall, and the National Hurricane Center warned about flash flooding and mudslides in southern and southeastern Mexico.
The National Hurricane Center issued the final bulletin on the remnants of Boris on June 4 at 2100 UTC (5 p.m. EDT). At that time, the center of the remnant low pressure area was near 16.5 north latitude and 94.0 west longitude, about 80 miles east of Salina Cruz, Mexico. As has been the case with Boris for days, its remnants continued to move slowly and were only tracking north at 1 knot (1.1 mph/1.8 kph) per hour. Maximum sustained winds 20 knots (23 mph/37 kph).
At that time Boris no longer qualified as a tropical cyclone and it was merging with System 90L located in the Bay of Campeche.
On Thursday, June 5, System 90L appeared to be coming together with the remnant moisture from Boris. Forecasters have been watching System 90L most of the past week, and until Boris made its way across southern Mexico, the system had a low chance for development. Now System 90L has a medium chance for becoming a tropical depression, according to the National Hurricane Center (NHC).
System 90L was centered near 19.3 north and 94.3 west, in the Bay of Campeche. The Bay of Campeche is part of the southwestern Gulf of Mexico and is surrounded on three sides by the Mexican states of Veracruz, Campeche, and Tabasco.
At 8 a.m. EDT, NHC noted that System 90L's showers and thunderstorms had increased and that despite strong upper-level winds, some further development of this system is possible over the next day or two if the low remains offshore of eastern Mexico.
Mexico's National Meteorological Service cautioned today, June 5, that heavy rainfall is possible in the states of the Yucatan Peninsula, southeastern and eastern Mexico. For updated forecasts in Spanish, visit: http://smn.cna.gob.mx.
At NASA's Goddard Space Flight Center in Greenbelt, Maryland, data from the Tropical Rainfall Measuring Mission (TRMM) satellite data was used to compile totals of the already soaking rains from Boris. The TRMM data showed that some areas in southwestern Mexico received over 12 inches of rainfall from Boris, while System 90L on the eastern side of Mexico brought similar totals to parts of the Yucatan.
Boris may be gone now, but System 90L has the potential to produce extremely heavy rains and life-threatening flash floods and mud slides over portions of southeastern Mexico during the next few days.
Text credit: Rob Gutro
NASA's Goddard Space Flight Center
[image-124][image-140]June 04, 2014 - NASA Sees Depression Boris Moving over Mexico With Heavy Rainfall
Tropical Depression 2E strengthened into Tropical Storm Boris briefly on June 3 before making landfall in southern Mexico and weakening into a depression. While Boris was building to tropical storm strength, NASA's Aqua and TRMM satellites passed overhead identifying heavy rainfall and the extent of the storm.
On June 3 at 19:15 UTC (3:15 p.m. EDT) the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Aqua satellite captured a visible image of Tropical Storm Boris over Central America. Boris appeared circular in the imagery and its clouds covered southern Mexico and stretched over the border into northern Guatemala. The MODIS image also showed that clouds associated with a low pressure in the southwestern Gulf of Mexico, specifically, in the Bay of Campeche, were just to the north of Boris.
Earlier in the day at 06:02 UTC (2:02 a.m. EDT), NASA and the Japan Aerospace Exploration Agency's Tropical Rainfall Measuring Mission (TRMM) satellite passed over Boris. TRMM gathered data about rainfall rates occurring within the depression (at the time). TRMM showed that rain near the center was falling at a rate of over 61 mm (2.4 inches) per hour. A National Hurricane Center (NHC) discussion at the time noted "The cloud pattern has become elongated and is possible that the low-level center is on the southern edge of the convection due to wind shear. This is supported by a 0600 UTC TRMM pass which shows what appears to be a center located south of the thunderstorm activity."
At 5 p.m. EDT on June 3 Boris' maximum sustained winds increased to 40 mph (65 kph) and the storm was named and classified as a tropical storm. Boris made landfall around 06:00 UTC (2 a.m. EDT) today, June 4. By 11 a.m. EDT, Boris had weakened to a tropical depression but was soaking southern Mexico.
The National Hurricane Center (NHC) noted that heavy rain and flash flooding remains a threat as Boris moves slowly over southern Mexico.
At 11 a.m. EDT on June 4, Boris was centered near 16.4 north latitude and 94.0 west longitude, about 80 miles (130 km) east of Salina Cruz, Mexico. Maximum sustained winds were near 30 mph (45 kph). Boris was crawling to the north at 2 mph (4 kph).
As indicated by the earlier TRMM satellite image, heavy rainfall is a component of Boris, and its slow movement is exacerbating the localized rainfall amounts. The National Hurricane Center noted that "Boris could still produce additional rainfall amounts of 4 to 8 inches with isolated amounts of up to 10 inches over the Mexican states of Oaxaca, Chiapas, Veracruz and Tabasco. These rains will bring isolated storm total amounts to as much as 20 inches especially over the higher terrain. These rains are likely to result in life-threatening flash floods and mud slides."
The Mexican Weather Service reported the city of Tonala on the coast of Chiapas has already recorded 12.5 inches (318 mm) of storm-total rainfall.
NHC expects that Boris will dissipate later today while it moves slowly northward and becomes a part of a large trough of low pressure extending from across the Isthmus of Tehuantepec northward into the Bay of Campeche. Once together, NHC expects the two systems to continue to produce very heavy rainfall over parts of Mexico.
Text credit: Rob Gutro
NASA's Goddard Space Flight Center
[image-92][image-108]June 03, 2014 - NASA Infrared Imagery Sees Heavy Rain Potential in Tropical Depression 2E
NASA's Aqua satellite captured an infrared image of Tropical Depression 2E that revealed high, very cold cloud top temperatures. Strong thunderstorms with cold cloud top temperatures that reach high into the troposphere have the potential to drop heavy rainfall amounts, and the National Hurricane Center has forecast large rainfall for the southern region of Mexico over the next couple of days.
A Tropical Storm Warning is in effect for Salina Cruz to the Mexico and Guatemala border as the depression remained stationary near the southwestern coast of Mexico on June 3.
NASA's Aqua satellite passed over Tropical Depression 2E on June 3 at 08:17 UTC (4:17 a.m. EDT) and gathered data about the depression's cloud temperatures. The Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite provided that infrared data. A false-colored image of the cloud temperatures was created at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California using the infrared data.
The AIRS image showed very cold cloud top temperatures in the depression indicating that the thunderstorms had strong uplift that pushed cloud tops near the top of the troposphere. Temperatures drop to just under 220 degrees kelvin (-63.6 F/-53.1C) at the top of the troposphere (and where the tropopause begins). Some of the depression's storms had cloud tops that cold and that high. An analysis of AIRS data indicated that storms that high in the troposphere have the potential for heavy rainfall.
Coupled with the potential for heavy rainfall, and the slow movement of Tropical Depression 2E, the National Hurricane Center (NHC) noted in its bulletin at 8 a.m. EDT (5 a.m. PDT) that rainfall totals may be extreme over a large part of southern Mexico.
According to NHC: tropical Depression 2E is expected to produce as much as 10 to 20 inches of rain over a large part of southern Mexico through Saturday...with isolated amounts exceeding 30 inches likely over the mountainous terrain of the Mexican states of Oaxaca and Chiapas. Tropical Depression 2E is also expected to produce total rainfall amounts of 5 to 10 inches in Guatemala. These rains are likely to result in life-threatening flash floods and mud slides.
At 8 a.m. EDT (5 a.m. PDT), Tropical Depression 2E's maximum sustained winds were near 35 mph (55 kph). It was stationary about 140 miles (220 km) south-southeast of Salina Cruz, Mexico near 14.4 north latitude and 94.3 west longitude. The depression's minimum central pressure was 1002 millibars. NHC expects the depression to being moving slowly northward later today, June 3 and near the coast in the warning area on June 4.
Another factor that hurricane forecasters at NHC are dealing in the forecast of Tropical Depression 2E is the interaction with a low pressure area in the Bay of Campeche on the Gulf of Mexico side of Mexico. The depression is also interacting with an upper-low pressure area as well as the Gulf system, making for a complicated scenario.
Forecaster Blake at the NHC noted during the 8 a.m. EDT discussion that some strengthening is possible before landfall in a day or so, although significant strengthening is not expected due to land interaction and the poor initial structure.
Text credit: Rob Gutro
NASA's Goddard Space Flight Center
[image-51][image-78]June 02, 2014 - NASA's TRMM Satellite Sees Eastern Pacific Tropical Cyclone Forming
There's a new tropical low pressure area brewing in the Eastern Pacific and NASA's TRMM satellite flew overhead and got a read on its rainfall rates and cloud heights.
The eastern Pacific Ocean has become active on cue with the start of the hurricane season in that area. Only a few days after hurricane Amanda weakened and disappeared the National Hurricane Center (NHC) said that development of another tropical cyclone is probable southeast of Salina Cruz, Mexico. NASA and the Japan Aerospace Exploration Agency's Tropical Rainfall Measuring Mission or TRMM satellite captured rainfall data on System 93E on June 2, 2014 at 0659 UTC (2:59 a.m. EDT).
At NASA's Goddard Space Flight Center in Greenbelt, Maryland, TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) data were overlaid on an enhanced infrared image from NOAA's GOES-EAST satellite received at 0645 UTC (02:45 a.m. EDT) on June 2. TRMM found areas of moderate to heavy rainfall in showers and thunderstorms within the area of this tropical low. However, the heaviest rainfall found by TRMM in the area covered by this image was 115.8 mm (4.6 inches) per hour in another area of disturbed weather over Belize.
At 2 p.m. EDT, the National Hurricane Center update noted that showers and thunderstorms associated with a low pressure area became better organized during the morning hours. System 93E is located 250 miles south-southeast of Salina Cruz, Mexico,
Because the environmental conditions are conducive for additional development, The National Hurricane Center expects a tropical depression may likely form later today or tonight as the low moves slowly northeastward or northward.
Even though the low has not yet become a depression, the National Hurricane Center reported that it continues to bring very heavy rainfall to portions of western Central America, and is expected to spread over southeastern Mexico during the next couple of days. These rains could cause life-threatening flash floods and mud slides in areas of mountainous terrain.
As of June 2 at 2 p.m. EDT (11 a.m. EDT), the National Hurricane Center gives System 93E a 90 percent chance of becoming tropical depression 2E in the next 48 hours.
Text credit: Hal Pierce / Rob Gutro
SSAI / NASA's Goddard Space Flight Center
