WunderBlog Archive » Category 6™
Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.Haima Slams into Northern Philippines
Still raging at Category 4 strength, Typhoon Haima (dubbed Lawin in the Philippines) was moving into the northern Philippines on Wednesday night local time. As of 9:00 am EDT Wednesday (9:00 pm local time), Haima was located about 235 miles northeast of Manila, moving west-northwest at about 19 mph. Haima became Earth’s seventh Category 5 storm of the year on Tuesday, with top sustained winds peaking at 165 mph and a minimum central pressure estimated at 900 mb by the Japan Meteorological Agency. Interactions with the mountainous island of Luzon have since chipped away at Haima’s strength. Top sustained winds were down to 120 knots (140 mph) as of 9 am EDT Wednesday. As noted by Jonathan Erdman (weather.com), if Haima makes landfall with sustained winds of at least 113 knots (130 mph), it will be the first Category 4 storm to strike northeast Luzon since Naigae in September 2011.
Figure 1. Enhanced infrared image from Japan’s Himawari-8 satellite of Typhoon Haima as of 1430Z (10:30 pm local time or 10:30 am EDT) Wednesday, October 19, 2016. Image credit: NOAA/NESDIS.
Figure 2. Radar imagery from Aparri, on the north coast of Luzon, shows the center of Typhoon Haima approaching at 10:00 am EDT (10:00 pm local time) Wednesday, October 19, 2016. Image credit: PAGASA.
Haima remained a gigantic and powerful typhoon as it approached Luzon, with hurricane-force winds extending out up to 75 miles from its center and tropical-storm force winds extending up to 235 miles. Fortunately, the winds on the stronger right-hand side of Haima, north of its center, will deliver their greatest punch to a fairly sparsely populated stretch of coastline in far northeast Luzon. A storm surge of up to 10 feet is possible within bays in this region, according to the Philippine Atmospheric, Geophysical and Astronomical Service Administration. There are no cities along this coast the size of Tacloban City, where the storm surge associated with Super Typhoon Haiyan killed more than 5000 people in 2013. The largest population center of far northeast Luzon is Tuguegarao City, located in the Cagayan Valley about 25 miles inland and shielded by a coastal range of mountains.
Given the size and strength of Haima, massive amounts of rain (10” - 20”, with higher amounts locally) can be expected over most of the northern half of the island of Luzon. These rains will fall atop ground saturated by the passage of former Category 4 Typhoon Sariki, which makes inland flooding the biggest concern from Haima. After exiting the Philippines, a weakened Haima will continue northwestward, making landfall on the China coast east of Hong Kong as a tropical storm or perhaps a Category 1 typhoon around Saturday night local time.
Figure 3. This “day-night band” image of Haima from the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi NPP satellite captures the storm while it was at super typhoon strength well east of the Philippines (outlined at far left) at 1642Z (12:42 pm EDT) Tuesday, October 18, 2016. Image credit: NOAA
99L unlikely to amount to much
Major development doesn’t appear to be in the cards for Invest 99L, a loosely organized, elongated cluster of showers and thunderstorms (convection) well east of the Bahamas. There is no closed circulation with 99L, and its convection remained paltry and fragmented from Tuesday night into Wednesday morning. Strong wind shear of around 30 - 35 knots continues to plague 99L, inhibiting organization of the convection that’s managing to hang on with the help of warm sea-surface temperatures (SSTs) of around 29°C (84°F) and a fairly moist atmosphere (mid-level relative humidities around 65 - 75%).
Figure 4. Enhanced infrared image of showers and thunderstorms associated with 99L well east of the Bahamas as of 1415Z (10:15 am EDT) Wednesday, October 19, 2016. Image credit: NASA/MSFC Earth Science Office.
Outlook for 99L
As it drifts northward and then northwestward over the next couple of days, 99L will move over progressively cooler SSTs as strong wind shear continues. About half of the members of the 00Z Wednesday GFS and ECMWF ensembles develop 99L to low-end tropical storm strength for a brief period, mostly around Thursday or Friday, when a strong upper-level trough will be approaching the eastern U.S. The dynamics associated with this trough, together with an upper-level low situated near 99L, would tend to favor 99L developing as a subtropical storm (if it did intensify) and eventually merging with the front. In its 8 am EDT Wednesday Tropical Weather Outlook, the National Hurricane Center is giving 99L a 60% chance of developing into at least a tropical depression by Friday and an 80% chance by Monday. I would peg the odds of 99L becoming a named tropical or subtropical storm at less than 50%. Meanwhile, the approaching front is expected to produce heavy rains of 2” - 6” from eastern Pennsylvania across upstate New York, northern New England, and far southeast Canada.
In the Eastern Pacific, NHC is monitoring three areas of interest, none of which are likely to develop over at least the next couple of days.
Figure 5. Surface winds over and near Greenland show the circulation associated with former Nicole as of 1500Z (11:00 am EDT) Wednesday, October 19, 2016.
Ex-Nicole helps trigger fierce downslope winds over southeast Greenland
After nearly two weeks as a tropical cyclone roaming the Atlantic, including a direct hit on Bermuda as a Category 3 hurricane, the remnants of Post-Tropical Cyclone Nicole were delivering a noteworthy parting shot to Greenland in the form of a localized wind called the piteraq (“that which attacks you”). A piteraq involves very cold, dense surface air descending from the Greenland plateau and accelerating in response to strong low pressure off the east coast. The EUMETSAT agency has an excellent explainer on the piteraq. Gradually being enveloped by a larger mid-latitude cyclone and front, Nicole was approaching far south Greenland on Wednesday as a still-powerful 966-millibar low, providing the strong pressure gradient needed for a piteraq to develop. Winds were sustained as high as 47 mph and gusting up to 68 mph on Wednesday morning at Tasillaq, on Greenland’s east coast, where coastal obstructions can cause a piteraq to evolve into an even more localized wind called a neqajaq. Thanks to wunderground member barbamz for finding and posting background information on the piteraq in the comments of our last post.
We’ll be back on Thursday with a new post.
Bob Henson
Figure 1. Enhanced infrared image from Japan’s Himawari-8 satellite of Typhoon Haima as of 1430Z (10:30 pm local time or 10:30 am EDT) Wednesday, October 19, 2016. Image credit: NOAA/NESDIS.
Figure 2. Radar imagery from Aparri, on the north coast of Luzon, shows the center of Typhoon Haima approaching at 10:00 am EDT (10:00 pm local time) Wednesday, October 19, 2016. Image credit: PAGASA.
Haima remained a gigantic and powerful typhoon as it approached Luzon, with hurricane-force winds extending out up to 75 miles from its center and tropical-storm force winds extending up to 235 miles. Fortunately, the winds on the stronger right-hand side of Haima, north of its center, will deliver their greatest punch to a fairly sparsely populated stretch of coastline in far northeast Luzon. A storm surge of up to 10 feet is possible within bays in this region, according to the Philippine Atmospheric, Geophysical and Astronomical Service Administration. There are no cities along this coast the size of Tacloban City, where the storm surge associated with Super Typhoon Haiyan killed more than 5000 people in 2013. The largest population center of far northeast Luzon is Tuguegarao City, located in the Cagayan Valley about 25 miles inland and shielded by a coastal range of mountains.
Given the size and strength of Haima, massive amounts of rain (10” - 20”, with higher amounts locally) can be expected over most of the northern half of the island of Luzon. These rains will fall atop ground saturated by the passage of former Category 4 Typhoon Sariki, which makes inland flooding the biggest concern from Haima. After exiting the Philippines, a weakened Haima will continue northwestward, making landfall on the China coast east of Hong Kong as a tropical storm or perhaps a Category 1 typhoon around Saturday night local time.
Figure 3. This “day-night band” image of Haima from the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi NPP satellite captures the storm while it was at super typhoon strength well east of the Philippines (outlined at far left) at 1642Z (12:42 pm EDT) Tuesday, October 18, 2016. Image credit: NOAA
99L unlikely to amount to much
Major development doesn’t appear to be in the cards for Invest 99L, a loosely organized, elongated cluster of showers and thunderstorms (convection) well east of the Bahamas. There is no closed circulation with 99L, and its convection remained paltry and fragmented from Tuesday night into Wednesday morning. Strong wind shear of around 30 - 35 knots continues to plague 99L, inhibiting organization of the convection that’s managing to hang on with the help of warm sea-surface temperatures (SSTs) of around 29°C (84°F) and a fairly moist atmosphere (mid-level relative humidities around 65 - 75%).
Figure 4. Enhanced infrared image of showers and thunderstorms associated with 99L well east of the Bahamas as of 1415Z (10:15 am EDT) Wednesday, October 19, 2016. Image credit: NASA/MSFC Earth Science Office.
Outlook for 99L
As it drifts northward and then northwestward over the next couple of days, 99L will move over progressively cooler SSTs as strong wind shear continues. About half of the members of the 00Z Wednesday GFS and ECMWF ensembles develop 99L to low-end tropical storm strength for a brief period, mostly around Thursday or Friday, when a strong upper-level trough will be approaching the eastern U.S. The dynamics associated with this trough, together with an upper-level low situated near 99L, would tend to favor 99L developing as a subtropical storm (if it did intensify) and eventually merging with the front. In its 8 am EDT Wednesday Tropical Weather Outlook, the National Hurricane Center is giving 99L a 60% chance of developing into at least a tropical depression by Friday and an 80% chance by Monday. I would peg the odds of 99L becoming a named tropical or subtropical storm at less than 50%. Meanwhile, the approaching front is expected to produce heavy rains of 2” - 6” from eastern Pennsylvania across upstate New York, northern New England, and far southeast Canada.
In the Eastern Pacific, NHC is monitoring three areas of interest, none of which are likely to develop over at least the next couple of days.
Figure 5. Surface winds over and near Greenland show the circulation associated with former Nicole as of 1500Z (11:00 am EDT) Wednesday, October 19, 2016.
Ex-Nicole helps trigger fierce downslope winds over southeast Greenland
After nearly two weeks as a tropical cyclone roaming the Atlantic, including a direct hit on Bermuda as a Category 3 hurricane, the remnants of Post-Tropical Cyclone Nicole were delivering a noteworthy parting shot to Greenland in the form of a localized wind called the piteraq (“that which attacks you”). A piteraq involves very cold, dense surface air descending from the Greenland plateau and accelerating in response to strong low pressure off the east coast. The EUMETSAT agency has an excellent explainer on the piteraq. Gradually being enveloped by a larger mid-latitude cyclone and front, Nicole was approaching far south Greenland on Wednesday as a still-powerful 966-millibar low, providing the strong pressure gradient needed for a piteraq to develop. Winds were sustained as high as 47 mph and gusting up to 68 mph on Wednesday morning at Tasillaq, on Greenland’s east coast, where coastal obstructions can cause a piteraq to evolve into an even more localized wind called a neqajaq. Thanks to wunderground member barbamz for finding and posting background information on the piteraq in the comments of our last post.
We’ll be back on Thursday with a new post.
Bob Henson
#Himawari visible imagery of Super Typhoon #Haima today pic.twitter.com/hrDM7WAlSF
— Dan Lindsey (@DanLindsey77) October 19, 2016
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